In order to obtain higher conversion efficiency and to reduce production cost for hydrogenated amorphous silicon/crystalline silicon(a-Si:H/c-Si) based heterojunction solar cells, an a-Si:H/c-Si heterojunction with lo...In order to obtain higher conversion efficiency and to reduce production cost for hydrogenated amorphous silicon/crystalline silicon(a-Si:H/c-Si) based heterojunction solar cells, an a-Si:H/c-Si heterojunction with localized p–n structure(HACL) is designed. A numerical simulation is performed with the ATLAS program. The effect of the a-Si:H layer on the performance of the HIT(heterojunction with intrinsic thin film) solar cell is investigated. The performance improvement mechanism for the HACL cell is explored. The potential performance of the HACL solar cell is compared with those of the HIT and HACD(heterojunction of amorphous silicon and crystalline silicon with diffused junction) solar cells.The simulated results indicate that the a-Si:H layer can bring about much absorption loss. The conversion efficiency and the short-circuit current density of the HACL cell can reach 28.18% and 43.06 m A/cm^2, respectively, and are higher than those of the HIT and HACD solar cells. The great improvement are attributed to(1) decrease of optical absorption loss of a-Si:H and(2) decrease of photocarrier recombination for the HACL cell. The double-side local junction is very suitable for the bifacial solar cells. For an HACL cell with n-type or p-type c-Si base, all n-type or p-type c-Si passivating layers are feasible for convenience of the double-side diffusion process. Moreover, the HACL structure can reduce the consumption of rare materials since the transparent conductive oxide(TCO) can be free in this structure. It is concluded that the HACL solar cell is a promising structure for high efficiency and low cost.展开更多
Hydrogen is a ubiquitous element in semiconductor processing and particularly in amorphous and microcrystalline silicon where it plays a crucial role in the growth processes as well as in the material properties. Beca...Hydrogen is a ubiquitous element in semiconductor processing and particularly in amorphous and microcrystalline silicon where it plays a crucial role in the growth processes as well as in the material properties. Because of its low mass it can easily diffuse through the silicon network and leads to the passivation of dangling bonds but it may also play a role in the stabilization of metastable defects. Thus a lot of work has been devoted to the study of hydrogen diffusion, bonding and structure in disordered semiconductors. The sequence, deposition-exposure to H plasma-deposition was used to fabricate the microcrystalline emitter. A proper atomic H pretreatment of c-Si surface before depositions i layer was expected to clean the surface and passivatates the surface states, as a result improing the device parameters. In this study, H2 pretreatment of c-si surface was used at different time, power and temperature. It is found that a proper H pretreatment improves passivation of c-si surface and improves the device parameters by AFM and testing I-V.展开更多
The tunnel-recombination junction(TRJ) and optical absorption properties of a-Si:H/a-Si Ge:H double-junction solar cell were calculated by means of one dimensional simulator named AMPS-1D at the radiation of AM1.5G wi...The tunnel-recombination junction(TRJ) and optical absorption properties of a-Si:H/a-Si Ge:H double-junction solar cell were calculated by means of one dimensional simulator named AMPS-1D at the radiation of AM1.5G with a power density of 100 m W/cm2. Since the TRJ is the core component of the tandem solar cell, the optical absorption of the sub-cells and the electronic transport properties at the interface of the sub-cells are affected by the thickness and doping concentration of the TRJ. As a result, the TRJ parameters were optimized. The numerical results indicate that the maximum conversion efficiency(Eff) of 9.862% can be obtained when the thickness and doping concentration of the TRJ are 10 nm and 5*1019 cm–3, respectively. Based on the analysis of the contour map of short circuit current density, the optimal current matching can be achieved for 130 nm-thick top i-layer and 250 nm-thick bottom i-layer. In addition, four kinds of TRJ structures were also simulated for the comparison purpose. According to the calculated resistivity and band structures of the four TRJs, the efficiency of the solar cell with n-type μc-Si:H layer and p-type a-Si:H layer in TRJ structure is greater than that with other TRJ structures. It is assumed that the effect of the band offset that results in the formation of triangular barrier and backscattering behavior at the edge of the TRJ could be responsible to this phenomenon.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2018YFB1500403)the National Natural Science Foundation of China(Grant Nos.11964018,61741404,and 61464007)the Natural Science Foundation of Jiangxi Province of China(Grant No.20181BAB202027)
文摘In order to obtain higher conversion efficiency and to reduce production cost for hydrogenated amorphous silicon/crystalline silicon(a-Si:H/c-Si) based heterojunction solar cells, an a-Si:H/c-Si heterojunction with localized p–n structure(HACL) is designed. A numerical simulation is performed with the ATLAS program. The effect of the a-Si:H layer on the performance of the HIT(heterojunction with intrinsic thin film) solar cell is investigated. The performance improvement mechanism for the HACL cell is explored. The potential performance of the HACL solar cell is compared with those of the HIT and HACD(heterojunction of amorphous silicon and crystalline silicon with diffused junction) solar cells.The simulated results indicate that the a-Si:H layer can bring about much absorption loss. The conversion efficiency and the short-circuit current density of the HACL cell can reach 28.18% and 43.06 m A/cm^2, respectively, and are higher than those of the HIT and HACD solar cells. The great improvement are attributed to(1) decrease of optical absorption loss of a-Si:H and(2) decrease of photocarrier recombination for the HACL cell. The double-side local junction is very suitable for the bifacial solar cells. For an HACL cell with n-type or p-type c-Si base, all n-type or p-type c-Si passivating layers are feasible for convenience of the double-side diffusion process. Moreover, the HACL structure can reduce the consumption of rare materials since the transparent conductive oxide(TCO) can be free in this structure. It is concluded that the HACL solar cell is a promising structure for high efficiency and low cost.
基金This project was financially supported by the Natural Science Foundation of Hebei Province, China (No.F2005000073).
文摘Hydrogen is a ubiquitous element in semiconductor processing and particularly in amorphous and microcrystalline silicon where it plays a crucial role in the growth processes as well as in the material properties. Because of its low mass it can easily diffuse through the silicon network and leads to the passivation of dangling bonds but it may also play a role in the stabilization of metastable defects. Thus a lot of work has been devoted to the study of hydrogen diffusion, bonding and structure in disordered semiconductors. The sequence, deposition-exposure to H plasma-deposition was used to fabricate the microcrystalline emitter. A proper atomic H pretreatment of c-Si surface before depositions i layer was expected to clean the surface and passivatates the surface states, as a result improing the device parameters. In this study, H2 pretreatment of c-si surface was used at different time, power and temperature. It is found that a proper H pretreatment improves passivation of c-si surface and improves the device parameters by AFM and testing I-V.
基金financially supported by the National Science Foundation of China (No. 11274266)the Key Project of Applied Basic Research Project of Yunnan Province of China (No. 2013FA029)the Open Project of National Laboratory for Infrared Physics (No. M201405)
文摘The tunnel-recombination junction(TRJ) and optical absorption properties of a-Si:H/a-Si Ge:H double-junction solar cell were calculated by means of one dimensional simulator named AMPS-1D at the radiation of AM1.5G with a power density of 100 m W/cm2. Since the TRJ is the core component of the tandem solar cell, the optical absorption of the sub-cells and the electronic transport properties at the interface of the sub-cells are affected by the thickness and doping concentration of the TRJ. As a result, the TRJ parameters were optimized. The numerical results indicate that the maximum conversion efficiency(Eff) of 9.862% can be obtained when the thickness and doping concentration of the TRJ are 10 nm and 5*1019 cm–3, respectively. Based on the analysis of the contour map of short circuit current density, the optimal current matching can be achieved for 130 nm-thick top i-layer and 250 nm-thick bottom i-layer. In addition, four kinds of TRJ structures were also simulated for the comparison purpose. According to the calculated resistivity and band structures of the four TRJs, the efficiency of the solar cell with n-type μc-Si:H layer and p-type a-Si:H layer in TRJ structure is greater than that with other TRJ structures. It is assumed that the effect of the band offset that results in the formation of triangular barrier and backscattering behavior at the edge of the TRJ could be responsible to this phenomenon.
