An effective and low-cost front-side anti-reflection(AR) technique has long been sought to enhance the performance of highly efficient photovoltaic devices due to its capability of maximizing the light absorption in p...An effective and low-cost front-side anti-reflection(AR) technique has long been sought to enhance the performance of highly efficient photovoltaic devices due to its capability of maximizing the light absorption in photovoltaic devices. In order to achieve high throughput fabrication of nanostructured flexible and anti-reflection films, large-scale, nano-engineered wafer molds were fabricated in this work. Additionally, to gain in-depth understanding of the optical and electrical performance enhancement with AR films on polycrystalline Si solar cells, both theoretical and experimental studies were performed. Intriguingly,the nanocone structures demonstrated an efficient light trapping effect which reduced the surface reflection of a solar cell by17.7% and therefore enhanced the overall electric output power of photovoltaic devices by 6% at normal light incidence. Notably, the output power improvement is even more significant at a larger light incident angle which is practically meaningful for daily operation of solar panels. The application of the developed AR films is not only limited to crystalline Si solar cells explored here, but also compatible with any types of photovoltaic technology for performance enhancement.展开更多
The device performance of CdS/CdTe solar cells largely depends on not only the back ohmic contact, but also the conformality of Cd S window layer coating. In order to reduce the light absorption loss in Cd S, the Cd S...The device performance of CdS/CdTe solar cells largely depends on not only the back ohmic contact, but also the conformality of Cd S window layer coating. In order to reduce the light absorption loss in Cd S, the Cd S thickness is usually less than 100 nm. However, pinholes in Cd S and non-conformal coverage of Cd S on transparent conducting oxide layer will cause shunting thus leading to device performance degradation and failure. In this paper, low-temperature and low-cost fabrication methods, i.e., chemical bath deposition and electrochemical deposition, were used to deposit Cd S and Cd Te, respectively. It was found that the yield of device was around 20 % due to shunting. In order to alleviate this problem, a compact layer of TiO2 was inserted between the fluorine-doped tin oxide and Cd S as a buffer layer. The thickness effect of TiO2 was studied and showed that devices with thin(20 nm thickness) TiO2 performed better than the counterparts with thick layers. It was discovered that device yield improved to 80 % and stability in air substantially improved with TiO2 layer.展开更多
基金supported by National Natural Science Foundation of China(Project No.51672231)Shen Zhen Science and Technology Innovation Commission(Project No.JCYJ20170818114107730)+1 种基金Hong Kong Research Grant Council(General Research Fund Project Nos.16237816,16309018)the support from the Center for 1D/2D Quantum Materials and the State Key Laboratory on Advanced Displays and Optoelectronics at HKUST
文摘An effective and low-cost front-side anti-reflection(AR) technique has long been sought to enhance the performance of highly efficient photovoltaic devices due to its capability of maximizing the light absorption in photovoltaic devices. In order to achieve high throughput fabrication of nanostructured flexible and anti-reflection films, large-scale, nano-engineered wafer molds were fabricated in this work. Additionally, to gain in-depth understanding of the optical and electrical performance enhancement with AR films on polycrystalline Si solar cells, both theoretical and experimental studies were performed. Intriguingly,the nanocone structures demonstrated an efficient light trapping effect which reduced the surface reflection of a solar cell by17.7% and therefore enhanced the overall electric output power of photovoltaic devices by 6% at normal light incidence. Notably, the output power improvement is even more significant at a larger light incident angle which is practically meaningful for daily operation of solar panels. The application of the developed AR films is not only limited to crystalline Si solar cells explored here, but also compatible with any types of photovoltaic technology for performance enhancement.
基金supported by Hong Kong Innovation Technology Commission project(ITS/117/13)Hong Kong Research Grants Council project(612113)+1 种基金Fundamental Research Project of Shenzhen Science & Technology Foundation(JCYJ20130402164725025)the International Collaboration Project of Shenzhen Science & Technology Foundation(GJHZ20130417170946221)
文摘The device performance of CdS/CdTe solar cells largely depends on not only the back ohmic contact, but also the conformality of Cd S window layer coating. In order to reduce the light absorption loss in Cd S, the Cd S thickness is usually less than 100 nm. However, pinholes in Cd S and non-conformal coverage of Cd S on transparent conducting oxide layer will cause shunting thus leading to device performance degradation and failure. In this paper, low-temperature and low-cost fabrication methods, i.e., chemical bath deposition and electrochemical deposition, were used to deposit Cd S and Cd Te, respectively. It was found that the yield of device was around 20 % due to shunting. In order to alleviate this problem, a compact layer of TiO2 was inserted between the fluorine-doped tin oxide and Cd S as a buffer layer. The thickness effect of TiO2 was studied and showed that devices with thin(20 nm thickness) TiO2 performed better than the counterparts with thick layers. It was discovered that device yield improved to 80 % and stability in air substantially improved with TiO2 layer.
