The optical absorption is the most important macroscopic process to characterize the microscopic optical transition in the semiconductor materials. Recently, great enhancement has been observed in the absorption of th...The optical absorption is the most important macroscopic process to characterize the microscopic optical transition in the semiconductor materials. Recently, great enhancement has been observed in the absorption of the active region within a p–n junction. In this paper, Ga As based p–i–n samples with the active region varied from 100 nm to 3 μm were fabricated and it was observed that the external quantum efficiencies are higher than the typical results, indicating a new mechanism beyond the established theories. We proposed a theoretical model about the abnormal optical absorption process in the active region within a strong electric field, which might provide new theories for the design of the solar cells,photodetectors, and other photoelectric devices.展开更多
We demonstrate that a low-temperature Ga N insertion layer could significantly improve the surface morphology of non-polar a-plane Ga N.The two key factors in improving the surface morphology of non-polar a-plane Ga N...We demonstrate that a low-temperature Ga N insertion layer could significantly improve the surface morphology of non-polar a-plane Ga N.The two key factors in improving the surface morphology of non-polar a-plane Ga N are growth temperature and growth time of the Ga N insertion layer.The root-mean-square roughness of a-plane Ga N is reduced by 75%compared to the sample without the Ga N insertion layer.Meanwhile,the Ga N insertion layer is also beneficial for improving crystal quality.This work provides a simple and effective method to improve the surface morphology of non-polar a-plane Ga N.展开更多
It is known that the p–n junction of an absorption region is a crucial part for power conversion efficiency of photovoltaic power converters.We fabricate four samples with different dopant concentrations in base laye...It is known that the p–n junction of an absorption region is a crucial part for power conversion efficiency of photovoltaic power converters.We fabricate four samples with different dopant concentrations in base layers.The dependences of power conversion efficiency and fill factor on input power are displayed by photocurrent–voltage measurement.Photoluminescence characteristics under open circuit and connected circuit conditions are also studied.It is found that the status of p–n junction matching is the critical factor in affecting the power conversion efficiency.In addition,series resistance of photovoltaic power converters impairs the efficiency especially at high input powers.Both the key factors need to be considered to obtain high efficiency,and this work provides promising guidance on designing photovoltaic power converters.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61991441)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000).
文摘The optical absorption is the most important macroscopic process to characterize the microscopic optical transition in the semiconductor materials. Recently, great enhancement has been observed in the absorption of the active region within a p–n junction. In this paper, Ga As based p–i–n samples with the active region varied from 100 nm to 3 μm were fabricated and it was observed that the external quantum efficiencies are higher than the typical results, indicating a new mechanism beyond the established theories. We proposed a theoretical model about the abnormal optical absorption process in the active region within a strong electric field, which might provide new theories for the design of the solar cells,photodetectors, and other photoelectric devices.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11574362 and 61704008)。
文摘We demonstrate that a low-temperature Ga N insertion layer could significantly improve the surface morphology of non-polar a-plane Ga N.The two key factors in improving the surface morphology of non-polar a-plane Ga N are growth temperature and growth time of the Ga N insertion layer.The root-mean-square roughness of a-plane Ga N is reduced by 75%compared to the sample without the Ga N insertion layer.Meanwhile,the Ga N insertion layer is also beneficial for improving crystal quality.This work provides a simple and effective method to improve the surface morphology of non-polar a-plane Ga N.
基金Supported by the National Natural Science Foundation of China(Grant Nos.61704008 and 11574362)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000).
文摘It is known that the p–n junction of an absorption region is a crucial part for power conversion efficiency of photovoltaic power converters.We fabricate four samples with different dopant concentrations in base layers.The dependences of power conversion efficiency and fill factor on input power are displayed by photocurrent–voltage measurement.Photoluminescence characteristics under open circuit and connected circuit conditions are also studied.It is found that the status of p–n junction matching is the critical factor in affecting the power conversion efficiency.In addition,series resistance of photovoltaic power converters impairs the efficiency especially at high input powers.Both the key factors need to be considered to obtain high efficiency,and this work provides promising guidance on designing photovoltaic power converters.
