Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of f...Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications.展开更多
Antimony selenide(Sb_(2)Se_(3))is an emerging solar cell material.Here,we demonstrate that an organic small molecule of 4,4',4''-tris(carbazol-9-yl)-triphenylamine(TCTA)can efficiently passivate the anode ...Antimony selenide(Sb_(2)Se_(3))is an emerging solar cell material.Here,we demonstrate that an organic small molecule of 4,4',4''-tris(carbazol-9-yl)-triphenylamine(TCTA)can efficiently passivate the anode interface of the Sb_(2)Se_(3)solar cell.We fabricated the device by the vacuum thermal evaporation,and took ITO/TCTA(3.0 nm)/Sb_(2)Se_(3)(50 nm)/C60(5.0 nm)/Alq3(3.0 nm)/Al as the device architecture,where Alq3 is the tris(8-hydroxyquinolinato)aluminum.By introducing a TCTA layer,the open-circuit voltage is raised from 0.36 to 0.42 V,and the power conversion efficiency is significantly improved from 3.2%to 4.3%.The TCTA layer not only inhibits the chemical reaction between the ITO and Sb_(2)Se_(3)during the annealing process but it also blocks the electron diffusion from Sb_(2)Se_(3)to ITO anode.The enhanced performance is mainly attributed to the suppression of the charge recombination at the anode interface.展开更多
The beneficial effect of the alkali metals such as Na and K on the Cu（In.Ga）Se2 （CIGS） and Cu2ZnSn（S,Se）4 （CZTSSe） solar cells has been extensively investigated in the past two decades, however, in most of the...The beneficial effect of the alkali metals such as Na and K on the Cu（In.Ga）Se2 （CIGS） and Cu2ZnSn（S,Se）4 （CZTSSe） solar cells has been extensively investigated in the past two decades, however, in most of the studies the alkali metals were treated as dopants. Several recent studies have showed that the alkali metals may not only act as dopants but also form secondary phases in the absorber layer or on the surfaces of the films. Using the first-principles calculations, we screened out the most probable secondary phases of Na and K in CIGS and CZTSSe, and studied their electronic structures and optical properties. We found that all these alkali chalcogenide compounds have larger band gaps and lower VBM levels than CIGS and CZTSSe, because the existence of strong p-d coupling in CIS and CZTS pushes the valence band maximum （VBM） level up and reduces the band-gaps, while there is no such p-d coupling in these alkali chalcogenides. This band alignment repels the photo-generated holes from the secondary phases and prevents the electron-hole recombination. Moreover, the study on the optical properties of the secondary phases showed that the absorption coefficients of these alkali chalcogenides are much lower than those of CIGS and CZTSSe in the energy range of 0-3.4eV, which means that the alkali chalcogenides may not influence the absorption of solar light. Since the alkali metal dopants can passivate the grain boundaries and increase the hole carrier concentration, and meanwhile their related secondary phases have innocuous effect on the optical absorption and band alignment, we can understand why the alkali metal dopants can improve the CIGS and CZTSSe solar cell performance.展开更多
In this paper, we investigated the effect of rapid thermal annealing （RTA） on solar cell performance. An opto-electric conversion efficiency of 11.75% （Voc = 0.64 V, Jsc = 25.88 mA/cm2, FF=72.08%） was obtained und...In this paper, we investigated the effect of rapid thermal annealing （RTA） on solar cell performance. An opto-electric conversion efficiency of 11.75% （Voc = 0.64 V, Jsc = 25.88 mA/cm2, FF=72.08%） was obtained under AM 1.5G when the cell was annealed at 300℃ for 30 s. The annealed solar cell showed an average absolute efficiency 1.5% higher than that of the as-deposited one. For the microstructure analysis and the physical phase confirmation, X-ray diffraction （XRD）, Raman spectra, front surface reflection （FSR）, internal quantum efficiency （IQE）, and X-ray photoelectron spectroscopy （XPS） were respectively applied to distinguish the causes inducing the efficiency variation. All experimental results implied that the RTA eliminated recombination centers at the p-n junction, reduced the surface optical losses, enhanced the blue response of the CdS buffer layer, and improved the ohmic contact between Mo and Cu（In, Ga）Se2 （CIGS） layers. This leaded to the improved performance of CIGS solar cell.展开更多
The lowest energies which make Cu,In,Ga,and Se atoms composing Cu（In,Ga）Se_2（CIGS） material displaced from their lattice sites are evaluated,respectively.The non-ionizing energy loss（NIEL） for electron in CIGS m...The lowest energies which make Cu,In,Ga,and Se atoms composing Cu（In,Ga）Se_2（CIGS） material displaced from their lattice sites are evaluated,respectively.The non-ionizing energy loss（NIEL） for electron in CIGS material is calculated analytically using the Mott differential cross section.The relation of the introduction rate（k） of the recombination centers to NIEL is modified,then the values of k at different electron energies are calculated.Degradation modeling of CIGS thin-film solar cells irradiated with various-energy electrons is performed according to the characterization of solar cells and the recombination centers.The validity of the modeling approach is verified by comparison with the experimental data.展开更多
The strong anisotropic electrical properties of one-dimensional(1 D) nanostructure semiconductors,especially the anisotropic carrier transport, have a negative and significant influence on the performance of solar cel...The strong anisotropic electrical properties of one-dimensional(1 D) nanostructure semiconductors,especially the anisotropic carrier transport, have a negative and significant influence on the performance of solar cells if the nanostructures have random orientation. Considering the advantages of nanorod solar cells in carrier transport, we have achieved growth of vertically aligned Sb_(2)Se_(3) nanorod array with highly(hk1) orientation on Cd S substrate, and constructed superstrate nanorod solar cells for the first time. The Sb_(2)Se_(3) nanorod array solar cells exhibit the more efficient and long-range carrier transport in vertical direction. Furthermore, in order to suppress interface recombination, a CuInSe_(2) quantum dots(QDs) sensitizer has been applied to fill the volume between the nanorods completely, thus forming an interpenetrating nanocomposite structure. The CuInSe_(2) QDs can harvest additional light by absorption of visible light and contribute photocurrent. Meantime, the QDs function as a hole transport material and thus reduce the dependence of lateral transport. Consequently, the interpenetrating nanocomposite CuInSe_(2) / Sb_(2)Se_(3) solar cells display a power conversion efficiency of 7.54% with significant enhancements in the short-circuit current density and open-circuit voltage over pure Sb_(2)Se_(3) nanorod cells. This is the highest efficiency for superstrate solar cells based on Sb_(2)Se_(3) nanorod arrays.展开更多
Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several years.The properties of Sb_(2)Se_(3)absorber and back conta...Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several years.The properties of Sb_(2)Se_(3)absorber and back contact influence the PV performances of Sb_(2)Se_(3)solar cells.Hence,optimization of back contact characteristics and absorber orientation are crucial steps in raising the power conversion efficiency(PCE)of Sb_(2)Se_(3)solar cells.In this work,MoO2was introduced as an intermediate layer(IL)in Sb_(2)Se_(3)solar cells,and comparative investigations were conducted.The growth of(211)-oriented Sb_(2)Se_(3)with large grains was facilitated by introducing the MoO2IL with suitable thickness.The MoO2IL substantially lowered the back contact barrier and prevented the formation of voids at the back contact,which reduced the thickness of the MoSe2interface layer,inhibited carrier recombination,and minimized bulk and interfacial defects in devices.Subsequently,significant optimization enhanced the open-circuit voltage(VOC)of solar cells from 0.481 V to 0.487 V,short-circuit current density(JSC)from 23.81 m A/cm^(2)to 29.29 m A/cm^(2),and fill factor from 50.28%to 57.10%,which boosted the PCE from 5.75%to 8.14%.展开更多
The Knudsen effusion cell is often used to grow high-quality Cu(In,Ga)Se_(2)(CIGS)thin film in coevaporation processes.However,the traditional single-heating Knudsen effusion cell cannot deliver complete metal selenid...The Knudsen effusion cell is often used to grow high-quality Cu(In,Ga)Se_(2)(CIGS)thin film in coevaporation processes.However,the traditional single-heating Knudsen effusion cell cannot deliver complete metal selenides during the whole deposition process,particularly for a low-temperature deposition process,which is probably due to the condensation and droplet ejection at the nozzle of the crucible.In this study,thermodynamics analysis is conducted to decipher the reason for this phenomenon.Furthermore,a new single-heating Knudsen effusion is proposed to solve this difficult problem,which leads to an improvement in the quality of CIGS film and a relative increase in conversion efficiency of 29%at a growth rate of about 230 nmmin1,compared with the traditional efficiency in a lowtemperature rapid-deposition process.展开更多
The band alignment at the front interfaces is crucial for the performance of Sb_(2)Se_(3) solar cell with superstrate configuration.Herein,a Sn O_(2)/Ti O_(2) thin film,demonstrated beneficial for carrier transport in...The band alignment at the front interfaces is crucial for the performance of Sb_(2)Se_(3) solar cell with superstrate configuration.Herein,a Sn O_(2)/Ti O_(2) thin film,demonstrated beneficial for carrier transport in Sb_(2)Se_(3) device by the first-principle calculation and experiment,is proposed to reduce the parasitic absorption caused by CdS and optimize the band alignment of Sb_(2)Se_(3) solar cell.Thanks to the desirable transmittance of SnO_(2)/TiO_(2) layer,the Sb_(2)Se_(3) solar cell with SnO_(2)/TiO_(2)/(CdS-38 nm) electron transport layer performances better than (CdS-70 nm)/Sb_(2)Se_(3) solar cell.The optimized band alignment,the reduced interface defects and the decreased current leakage of Sb_(2)Se_(3) solar cell enable the short-circuit current density,fill factor,open-circuit voltage and efficiency of the Sb_(2)Se_(3) solar cell increase by 26.7%,112%,33.1%and 250%respectively when comparing with TiO_(2)/Sb_(2)Se_(3) solar cell without modification.Finally,an easily prepared Sn O_(2)/Ti O_(2)/CdS ETL is successfully applied on Sb_(2)Se_(3) solar cell by the first time and contributes to the best efficiency of 7.0%in this work,which is remarkable for Sb_(2)Se_(3) solar cells free of hole transporting materials and toxic CdCl_(2) treatment.This work is expected to provide a valuable reference for future ETL design and band alignment for Sb_(2)Se_(3) solar cell and other optoelectronic devices.展开更多
High Ga content Cu(In,Ga)Se2 thin films incorporated sulfur were prepared by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds and subsequently Ga2Se3, In2Se3 and In2S3 binary compounds. The In2S3/(Ga2...High Ga content Cu(In,Ga)Se2 thin films incorporated sulfur were prepared by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds and subsequently Ga2Se3, In2Se3 and In2S3 binary compounds. The In2S3/(Ga2Se3+ In2Se3) ratio was varied from 0 to 0.13, and the properties of the thin films were investigated. XRD studies demonstrated that the prepared thin films had a chalcopyrite Cu(In,Ga)Se2 structure. The S/(Se+S) mole ratio in the thin films was within the range from 0 to 0.04. The band gaps of Cu(In,Ga)Se2 thin films increased from 1.30 eV to 1.59 eV with increasing the ?In2S3 /(Ga2Se3+ In2Se3) ratio.展开更多
Cu(In,Ga)Se_(2)(CIGS)is a promising candidate to replace crystalline silicon solar cells and dominate the photovoltaic market in the future.Alkali elements such as sodium(Na),potassium(K),rubidium(Rb),and Cesium(Cs)ar...Cu(In,Ga)Se_(2)(CIGS)is a promising candidate to replace crystalline silicon solar cells and dominate the photovoltaic market in the future.Alkali elements such as sodium(Na),potassium(K),rubidium(Rb),and Cesium(Cs)are commonly accepted as indispensable parts to boost cell efficiencies of CIGS thin-film solar cells.Therefore,a comprehensive understanding of alkali effects on the electronic and chemical properties of the CIGS layer as well as the underlying mechanisms is of paramount importance for achieving high-performance solar cells.This paper reviews the development process and incorporation pathways of alkalis and then overviews the roles of different alkali elements and their effects on CIGS cells in detail.Furthermore,the unsolved problems and future development prospects are also proposed.Overall,the understanding and development of widely adopted alkali-fluoride post-deposition treatments(PDTs)are still underway,and together with newly updated research,it will likely enable the CIGS technology to make the conversion efficiency closer to its theoretical limit.展开更多
Antimony selenide(Sb_(2)Se_(3))has drawn tremendous research attentions in recent years as an environment-friendly and cost-efficient photovoltaic material.However,the intrinsic low carrier density and electrical cond...Antimony selenide(Sb_(2)Se_(3))has drawn tremendous research attentions in recent years as an environment-friendly and cost-efficient photovoltaic material.However,the intrinsic low carrier density and electrical conductivity limited its scope of applications.In this work,an effective ion doping strategy was implemented to improve the electrical and photoelectrical performances of Sb_(2)Se_(3) thin films.The Sn-doped and I-doped Sb_(2)Se_(3) thin films with controllable chemical composition can be prepared by magnetron sputtering combined with post-selenization treatment based on homemade plasma sintered targets.As a result,the Sn-doped Sb_(2)Se_(3) thin film exhibited a great increase in carrier density by several orders of magnitude,by contrast,a less increase with one order of magnitude was achieved for the Idoped Sb_(2)Se_(3) thin film.Additionally,such cation or anion doping could simultaneously modify the conduction type of Sb_(2)Se_(3),enabling the first fabrication of a substrate structured Sb_(2)Se_(3)-based quasihomojunction thin film solar cell with configuration of Mo/Sb_(2)Se_(3)-Sn/Sb_(2)Se_(3)-I/ITO/Ag.The obtained power conversion efficiency exceeding 2%undoubtedly demonstrated its attractive photovoltaic application potential and further investigation necessity.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62104156,62074102)the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2023A1515011256,2022A1515010979)China+1 种基金Science and Technology plan project of Shenzhen(Grant Nos.20220808165025003,20200812000347001)Chinasupported by the open foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Guangxi University(Grant No.2022GXYSOF13)。
文摘Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications.
基金This work was supported by the High Level Talents Project Fund of Hainan Basic and Applied Research Program(NATURAL SCIENCE)(Grant No.2019RC118).
文摘Antimony selenide(Sb_(2)Se_(3))is an emerging solar cell material.Here,we demonstrate that an organic small molecule of 4,4',4''-tris(carbazol-9-yl)-triphenylamine(TCTA)can efficiently passivate the anode interface of the Sb_(2)Se_(3)solar cell.We fabricated the device by the vacuum thermal evaporation,and took ITO/TCTA(3.0 nm)/Sb_(2)Se_(3)(50 nm)/C60(5.0 nm)/Alq3(3.0 nm)/Al as the device architecture,where Alq3 is the tris(8-hydroxyquinolinato)aluminum.By introducing a TCTA layer,the open-circuit voltage is raised from 0.36 to 0.42 V,and the power conversion efficiency is significantly improved from 3.2%to 4.3%.The TCTA layer not only inhibits the chemical reaction between the ITO and Sb_(2)Se_(3)during the annealing process but it also blocks the electron diffusion from Sb_(2)Se_(3)to ITO anode.The enhanced performance is mainly attributed to the suppression of the charge recombination at the anode interface.
基金supported by the National Natural Science Foundation of China(NSFC)under grant nos.61574059 and 61722402the National Key Research and Development Program of China(2016YFB0700700)+1 种基金Shu-Guang program(15SG20)CC of ECNU
文摘The beneficial effect of the alkali metals such as Na and K on the Cu（In.Ga）Se2 （CIGS） and Cu2ZnSn（S,Se）4 （CZTSSe） solar cells has been extensively investigated in the past two decades, however, in most of the studies the alkali metals were treated as dopants. Several recent studies have showed that the alkali metals may not only act as dopants but also form secondary phases in the absorber layer or on the surfaces of the films. Using the first-principles calculations, we screened out the most probable secondary phases of Na and K in CIGS and CZTSSe, and studied their electronic structures and optical properties. We found that all these alkali chalcogenide compounds have larger band gaps and lower VBM levels than CIGS and CZTSSe, because the existence of strong p-d coupling in CIS and CZTS pushes the valence band maximum （VBM） level up and reduces the band-gaps, while there is no such p-d coupling in these alkali chalcogenides. This band alignment repels the photo-generated holes from the secondary phases and prevents the electron-hole recombination. Moreover, the study on the optical properties of the secondary phases showed that the absorption coefficients of these alkali chalcogenides are much lower than those of CIGS and CZTSSe in the energy range of 0-3.4eV, which means that the alkali chalcogenides may not influence the absorption of solar light. Since the alkali metal dopants can passivate the grain boundaries and increase the hole carrier concentration, and meanwhile their related secondary phases have innocuous effect on the optical absorption and band alignment, we can understand why the alkali metal dopants can improve the CIGS and CZTSSe solar cell performance.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60876045)the Shanghai Leading Basic Research Project, China (Grant No. 09JC1405900)+1 种基金the Shanghai Leading Academic Discipline Project, China (Grant No. S30105)the R & D Foundation of SHU-SOENs PV Joint Laboratory, China (Grant No. SS-E0700601)
文摘In this paper, we investigated the effect of rapid thermal annealing （RTA） on solar cell performance. An opto-electric conversion efficiency of 11.75% （Voc = 0.64 V, Jsc = 25.88 mA/cm2, FF=72.08%） was obtained under AM 1.5G when the cell was annealed at 300℃ for 30 s. The annealed solar cell showed an average absolute efficiency 1.5% higher than that of the as-deposited one. For the microstructure analysis and the physical phase confirmation, X-ray diffraction （XRD）, Raman spectra, front surface reflection （FSR）, internal quantum efficiency （IQE）, and X-ray photoelectron spectroscopy （XPS） were respectively applied to distinguish the causes inducing the efficiency variation. All experimental results implied that the RTA eliminated recombination centers at the p-n junction, reduced the surface optical losses, enhanced the blue response of the CdS buffer layer, and improved the ohmic contact between Mo and Cu（In, Ga）Se2 （CIGS） layers. This leaded to the improved performance of CIGS solar cell.
基金Project supported by the National Natural Science Foundation of China(Grant No.11547151)
文摘The lowest energies which make Cu,In,Ga,and Se atoms composing Cu（In,Ga）Se_2（CIGS） material displaced from their lattice sites are evaluated,respectively.The non-ionizing energy loss（NIEL） for electron in CIGS material is calculated analytically using the Mott differential cross section.The relation of the introduction rate（k） of the recombination centers to NIEL is modified,then the values of k at different electron energies are calculated.Degradation modeling of CIGS thin-film solar cells irradiated with various-energy electrons is performed according to the characterization of solar cells and the recombination centers.The validity of the modeling approach is verified by comparison with the experimental data.
基金financially supported by the National Key R&D Program of China (Grant No. 2019YFB1503400)the National Natural Science Foundation of China (Grant No. 61804064)the Natural Science Foundation of Guangdong Province (Grant No.2019A1515011616)。
文摘The strong anisotropic electrical properties of one-dimensional(1 D) nanostructure semiconductors,especially the anisotropic carrier transport, have a negative and significant influence on the performance of solar cells if the nanostructures have random orientation. Considering the advantages of nanorod solar cells in carrier transport, we have achieved growth of vertically aligned Sb_(2)Se_(3) nanorod array with highly(hk1) orientation on Cd S substrate, and constructed superstrate nanorod solar cells for the first time. The Sb_(2)Se_(3) nanorod array solar cells exhibit the more efficient and long-range carrier transport in vertical direction. Furthermore, in order to suppress interface recombination, a CuInSe_(2) quantum dots(QDs) sensitizer has been applied to fill the volume between the nanorods completely, thus forming an interpenetrating nanocomposite structure. The CuInSe_(2) QDs can harvest additional light by absorption of visible light and contribute photocurrent. Meantime, the QDs function as a hole transport material and thus reduce the dependence of lateral transport. Consequently, the interpenetrating nanocomposite CuInSe_(2) / Sb_(2)Se_(3) solar cells display a power conversion efficiency of 7.54% with significant enhancements in the short-circuit current density and open-circuit voltage over pure Sb_(2)Se_(3) nanorod cells. This is the highest efficiency for superstrate solar cells based on Sb_(2)Se_(3) nanorod arrays.
基金supported by the National Natural Science Foundation of China(62074102)the Guangdong Basic and Applied Basic Research Foundation(2022A1515010979)+1 种基金the Key Project of Department of Education of Guangdong Province(2018KZDXM059)the Science and Technology plan project of Shenzhen(20220808165025003)。
文摘Antimony selenide(Sb_(2)Se_(3))is a potential photovoltaic(PV)material for next-generation solar cells and has achieved great development in the last several years.The properties of Sb_(2)Se_(3)absorber and back contact influence the PV performances of Sb_(2)Se_(3)solar cells.Hence,optimization of back contact characteristics and absorber orientation are crucial steps in raising the power conversion efficiency(PCE)of Sb_(2)Se_(3)solar cells.In this work,MoO2was introduced as an intermediate layer(IL)in Sb_(2)Se_(3)solar cells,and comparative investigations were conducted.The growth of(211)-oriented Sb_(2)Se_(3)with large grains was facilitated by introducing the MoO2IL with suitable thickness.The MoO2IL substantially lowered the back contact barrier and prevented the formation of voids at the back contact,which reduced the thickness of the MoSe2interface layer,inhibited carrier recombination,and minimized bulk and interfacial defects in devices.Subsequently,significant optimization enhanced the open-circuit voltage(VOC)of solar cells from 0.481 V to 0.487 V,short-circuit current density(JSC)from 23.81 m A/cm^(2)to 29.29 m A/cm^(2),and fill factor from 50.28%to 57.10%,which boosted the PCE from 5.75%to 8.14%.
基金The work was supported by the National Key R&D Program of China(2018YFB1500200)the National Natural Science Foundation of China(61774089 and 61974076)the Natural Science Foundation of Tianjin(18JCZDJC31200).
文摘The Knudsen effusion cell is often used to grow high-quality Cu(In,Ga)Se_(2)(CIGS)thin film in coevaporation processes.However,the traditional single-heating Knudsen effusion cell cannot deliver complete metal selenides during the whole deposition process,particularly for a low-temperature deposition process,which is probably due to the condensation and droplet ejection at the nozzle of the crucible.In this study,thermodynamics analysis is conducted to decipher the reason for this phenomenon.Furthermore,a new single-heating Knudsen effusion is proposed to solve this difficult problem,which leads to an improvement in the quality of CIGS film and a relative increase in conversion efficiency of 29%at a growth rate of about 230 nmmin1,compared with the traditional efficiency in a lowtemperature rapid-deposition process.
基金supported by the National Key R&D Program of China(2019YFB1503500)the National Natural Science Foundation of China(U1902218,11774187)the Postgraduate Education Innovation Project of Tianjin,China(2021YJSB002)。
文摘The band alignment at the front interfaces is crucial for the performance of Sb_(2)Se_(3) solar cell with superstrate configuration.Herein,a Sn O_(2)/Ti O_(2) thin film,demonstrated beneficial for carrier transport in Sb_(2)Se_(3) device by the first-principle calculation and experiment,is proposed to reduce the parasitic absorption caused by CdS and optimize the band alignment of Sb_(2)Se_(3) solar cell.Thanks to the desirable transmittance of SnO_(2)/TiO_(2) layer,the Sb_(2)Se_(3) solar cell with SnO_(2)/TiO_(2)/(CdS-38 nm) electron transport layer performances better than (CdS-70 nm)/Sb_(2)Se_(3) solar cell.The optimized band alignment,the reduced interface defects and the decreased current leakage of Sb_(2)Se_(3) solar cell enable the short-circuit current density,fill factor,open-circuit voltage and efficiency of the Sb_(2)Se_(3) solar cell increase by 26.7%,112%,33.1%and 250%respectively when comparing with TiO_(2)/Sb_(2)Se_(3) solar cell without modification.Finally,an easily prepared Sn O_(2)/Ti O_(2)/CdS ETL is successfully applied on Sb_(2)Se_(3) solar cell by the first time and contributes to the best efficiency of 7.0%in this work,which is remarkable for Sb_(2)Se_(3) solar cells free of hole transporting materials and toxic CdCl_(2) treatment.This work is expected to provide a valuable reference for future ETL design and band alignment for Sb_(2)Se_(3) solar cell and other optoelectronic devices.
文摘High Ga content Cu(In,Ga)Se2 thin films incorporated sulfur were prepared by sequential evaporation from CuGaSe2 and CuInSe2 ternary compounds and subsequently Ga2Se3, In2Se3 and In2S3 binary compounds. The In2S3/(Ga2Se3+ In2Se3) ratio was varied from 0 to 0.13, and the properties of the thin films were investigated. XRD studies demonstrated that the prepared thin films had a chalcopyrite Cu(In,Ga)Se2 structure. The S/(Se+S) mole ratio in the thin films was within the range from 0 to 0.04. The band gaps of Cu(In,Ga)Se2 thin films increased from 1.30 eV to 1.59 eV with increasing the ?In2S3 /(Ga2Se3+ In2Se3) ratio.
基金supported by the National Natural Science Foundation of China(Nos.11975135 and 61176003)financial support of Special Funds for Fundamental Research Funds for Central Universities(No.2018 NTST29)the Chinese Postdoctoral Science Foundation(No.2019M650524)。
文摘Cu(In,Ga)Se_(2)(CIGS)is a promising candidate to replace crystalline silicon solar cells and dominate the photovoltaic market in the future.Alkali elements such as sodium(Na),potassium(K),rubidium(Rb),and Cesium(Cs)are commonly accepted as indispensable parts to boost cell efficiencies of CIGS thin-film solar cells.Therefore,a comprehensive understanding of alkali effects on the electronic and chemical properties of the CIGS layer as well as the underlying mechanisms is of paramount importance for achieving high-performance solar cells.This paper reviews the development process and incorporation pathways of alkalis and then overviews the roles of different alkali elements and their effects on CIGS cells in detail.Furthermore,the unsolved problems and future development prospects are also proposed.Overall,the understanding and development of widely adopted alkali-fluoride post-deposition treatments(PDTs)are still underway,and together with newly updated research,it will likely enable the CIGS technology to make the conversion efficiency closer to its theoretical limit.
基金supported by Natural Science Foundation of Guangdong Province(2020A1515010805)ChinaNational Natural Science Foundation of China(No.62074102)+1 种基金Key Project of Department of Education of Guangdong Province(No.2018KZDXM059)ChinaScience and Technology plan project of Shenzhen(JCYJ20190808153409238)China.
文摘Antimony selenide(Sb_(2)Se_(3))has drawn tremendous research attentions in recent years as an environment-friendly and cost-efficient photovoltaic material.However,the intrinsic low carrier density and electrical conductivity limited its scope of applications.In this work,an effective ion doping strategy was implemented to improve the electrical and photoelectrical performances of Sb_(2)Se_(3) thin films.The Sn-doped and I-doped Sb_(2)Se_(3) thin films with controllable chemical composition can be prepared by magnetron sputtering combined with post-selenization treatment based on homemade plasma sintered targets.As a result,the Sn-doped Sb_(2)Se_(3) thin film exhibited a great increase in carrier density by several orders of magnitude,by contrast,a less increase with one order of magnitude was achieved for the Idoped Sb_(2)Se_(3) thin film.Additionally,such cation or anion doping could simultaneously modify the conduction type of Sb_(2)Se_(3),enabling the first fabrication of a substrate structured Sb_(2)Se_(3)-based quasihomojunction thin film solar cell with configuration of Mo/Sb_(2)Se_(3)-Sn/Sb_(2)Se_(3)-I/ITO/Ag.The obtained power conversion efficiency exceeding 2%undoubtedly demonstrated its attractive photovoltaic application potential and further investigation necessity.
