Although silver(Ag) substitution offers several benefits in eliminating bulk defects and facilitating interface type inversion for Cu2ZnSn(S,Se)4(CZTSSe) photovoltaic(PV) technology, its further development is still h...Although silver(Ag) substitution offers several benefits in eliminating bulk defects and facilitating interface type inversion for Cu2ZnSn(S,Se)4(CZTSSe) photovoltaic(PV) technology, its further development is still hindered by the fairly low electrical conductivity due to the significant decrease of acceptors amount.In this work, a versatile Li–Ag co-doping strategy is demonstrated to mitigate the poor electrical conductivity arising from Ag through direct incorporating Li via postdeposition treatment(PDT) on top of the Ag-substituted CZTSSe absorber. Depth characterizations demonstrate that Li incorporation increases ptype carrier concentration, improves the carrier collection within the bulk, reduces the defects energy level as well as inverts the electric field polarity at grain boundaries(GBs) for Ag-substituted CZTSSe system. Benefiting from this lithium-assisted complex engineering of electrical performance both in grain interior(GI) and GBs, the power conversion efficiency(PCE) is finally increased from 9.21% to 10.29%. This systematic study represents an effective way to overcome the challenges encountered in Ag substitution,and these findings support a new aspect that the synergistic effects of double cation dopant will further pave the way for the development of high efficiency kesterite PV technology.展开更多
The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately ...The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.展开更多
The Y,F,and Ag tridoped TiO_(2)/SnO_(2) composite nanocrystalline film(YFAg–TS)with prominent photocatalytic performance was prepared by the modified sol–gel method and was characterized by utilizing X-ray diffracti...The Y,F,and Ag tridoped TiO_(2)/SnO_(2) composite nanocrystalline film(YFAg–TS)with prominent photocatalytic performance was prepared by the modified sol–gel method and was characterized by utilizing X-ray diffraction(XRD),differential thermal and thermogravimetric(DTA–TG)analysis,scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),Brunauer–Emmett–Teller(BET)method,ultraviolet–visible diffuse reflectance spectroscopy(UV–vis DRS),and photoluminescence(PL).The XRD and DTA–TG results expose that the YFAg–TS catalyst is a mixed phase consisting of anatase,rutile,and chlorargyrite,which is beneficial to improving the photocatalytic performance of TiO_(2).The SEM,TEM,and BET results disclose that the YFAg–TS film has smaller nanoparticles,higher specific surface area,and narrower pore size compared with pure TiO_(2) film.The XRD and TEM results exhibit that a part of yttrium can enter the TiO_(2) lattice to induce lattice distortion.The XPS results confirm the presence of Y^(3+)state in the YFAg–TS sample,and Y^(3+)ions can act as the trapping site of electrons to expedite the separation of electrons and holes.The UV–vis DRS results reveal that the YFAg–TS film has an obvious absorption edge shift and a narrower bandgap(2.70 eV)compared with pure TiO_(2) film.The PL results show that the YFAg–TS film has the highest photogenerated electrons and holes separation efficiency and charges transfer efficiency among all samples.The photocatalytic activity of the YFAg–TS was assessed by monitoring the degradation of methyl green and formaldehyde solution.The results manifest that the YFAg–TS film has high stability and excellent photocatalytic performance.The possible synergistic photocatalytic mechanism of YFAg–TS films has been discussed in this paper.展开更多
Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting ...Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting temperature and enlarge band gap of the CIGS films, were employed to enhance the quality of thin films in a low-temperature deposition process. It is demonstrated that both the Ag precursor and Ag surface treatment process can heighten the crystallinity of CIGS films and the device efficiency. The former is more obvious than the latter. Furthermore, the Urbach energy is also reduced with Ag doping. This work aims to provide a feasible Ag-doping process for the high-quality CIGS films in a low-temperature process.展开更多
基金the National Natural Science Foundation of China(61874159,61974173,51702085,51802081 and 21603058)the Joint Talent Cultivation Funds of NSFC-HN(U1704151)the Science and Technology Innovation Talents in Universities of Henan Province(18HASTIT016)。
文摘Although silver(Ag) substitution offers several benefits in eliminating bulk defects and facilitating interface type inversion for Cu2ZnSn(S,Se)4(CZTSSe) photovoltaic(PV) technology, its further development is still hindered by the fairly low electrical conductivity due to the significant decrease of acceptors amount.In this work, a versatile Li–Ag co-doping strategy is demonstrated to mitigate the poor electrical conductivity arising from Ag through direct incorporating Li via postdeposition treatment(PDT) on top of the Ag-substituted CZTSSe absorber. Depth characterizations demonstrate that Li incorporation increases ptype carrier concentration, improves the carrier collection within the bulk, reduces the defects energy level as well as inverts the electric field polarity at grain boundaries(GBs) for Ag-substituted CZTSSe system. Benefiting from this lithium-assisted complex engineering of electrical performance both in grain interior(GI) and GBs, the power conversion efficiency(PCE) is finally increased from 9.21% to 10.29%. This systematic study represents an effective way to overcome the challenges encountered in Ag substitution,and these findings support a new aspect that the synergistic effects of double cation dopant will further pave the way for the development of high efficiency kesterite PV technology.
基金supported by the Natural Science Foundation of Chongqing City(Grant Nos.CSTB2022NSCQ-MSX0751 and cstc2021jcyj-msxmX0500)the Education Department Project of Jilin Province(Grant No.JJKH20220726KJ)+1 种基金the Science and Technology Department Project of Jilin Province(Grant No.20200201077JC)the National Natural Science Foundation of China(Grant No.U2141239).
文摘The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.
基金Project supported by the Natural Science Foundation of Shandong Province (ZR2016BM30)。
文摘The Y,F,and Ag tridoped TiO_(2)/SnO_(2) composite nanocrystalline film(YFAg–TS)with prominent photocatalytic performance was prepared by the modified sol–gel method and was characterized by utilizing X-ray diffraction(XRD),differential thermal and thermogravimetric(DTA–TG)analysis,scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),Brunauer–Emmett–Teller(BET)method,ultraviolet–visible diffuse reflectance spectroscopy(UV–vis DRS),and photoluminescence(PL).The XRD and DTA–TG results expose that the YFAg–TS catalyst is a mixed phase consisting of anatase,rutile,and chlorargyrite,which is beneficial to improving the photocatalytic performance of TiO_(2).The SEM,TEM,and BET results disclose that the YFAg–TS film has smaller nanoparticles,higher specific surface area,and narrower pore size compared with pure TiO_(2) film.The XRD and TEM results exhibit that a part of yttrium can enter the TiO_(2) lattice to induce lattice distortion.The XPS results confirm the presence of Y^(3+)state in the YFAg–TS sample,and Y^(3+)ions can act as the trapping site of electrons to expedite the separation of electrons and holes.The UV–vis DRS results reveal that the YFAg–TS film has an obvious absorption edge shift and a narrower bandgap(2.70 eV)compared with pure TiO_(2) film.The PL results show that the YFAg–TS film has the highest photogenerated electrons and holes separation efficiency and charges transfer efficiency among all samples.The photocatalytic activity of the YFAg–TS was assessed by monitoring the degradation of methyl green and formaldehyde solution.The results manifest that the YFAg–TS film has high stability and excellent photocatalytic performance.The possible synergistic photocatalytic mechanism of YFAg–TS films has been discussed in this paper.
基金The work was supported by the National Key R&D Program of China(No.2018YFB1500200)National Natural Science Foundation of China(Nos.61774089 and 61974076)Natural Science Foundation of Tianjin(No.18JCZDJC31200)。
文摘Chalcopyrite Cu(In,Ga)Se_(2)(CIGS) thin films deposited in a low-temperature process(450℃) usually produce fine grains and poor crystallinity. Herein, different Ag treatment processes, which can decrease the melting temperature and enlarge band gap of the CIGS films, were employed to enhance the quality of thin films in a low-temperature deposition process. It is demonstrated that both the Ag precursor and Ag surface treatment process can heighten the crystallinity of CIGS films and the device efficiency. The former is more obvious than the latter. Furthermore, the Urbach energy is also reduced with Ag doping. This work aims to provide a feasible Ag-doping process for the high-quality CIGS films in a low-temperature process.
