Enhanced Photovoltaic Properties for Rear Passivated Crystalline Silicon Solar Cells by Fabricating Boron Doped Local Back Surface Field

In order to enhance the p-type doping concentration in the LBSF, boron was added into the aluminum paste and boron doped local back surface field（B-LBSF） was successfully fabricated in this work. Through boron doping in the LBSF, much higher doping concentration was observed for the B-LBSF over the Al-LBSF. Higher doping concentration in the LBSF is expected to lead to better rear passivation and lower rear contact resistance. Based on one thousand pieces of solar cells for each type, it was found that the rear passivated crystalline silicon solar cells with B-LBSF showed statistical improvement in their photovoltaic properties over those with Al-LBSF.

High-performance SiO_(x)/MgO_(x)electron-selective contacts for crystalline silicon solar cells

High carrier recombination loss at the metal and silicon contact regions is one of the dominant factors constraining the power conversion efficiency(PCE)of crystalline silicon(c-Si)solar cells.Metal compound-based carrier-selective contacts are being intensively developed to address this issue.In this work,we present a high-performance electron-selective SiO_(x)/MgO_(x)contact for c-Si solar cells.The SiO_(x)/MgO_(x)stack is prepared by thermally-grown SiO_(x)(∼0.7 nm)and thermally-evaporated MgO_(x)(~1.0 nm).The electron selectivity of SiO_(x)/MgO_(x)contact is investigated by measuring the surface passivation and the contact resistivity(ρ_(c))on the c-Si surface.The results demonstrate that optimized SiO_(x)/MgO_(x)contact displays a very lowρ_(c)(3.4 mΩcm^(2))and a good surface passivation on an n-type c-Si surface simultaneously.A high PCE of 21.1%is achieved on an n-type c-Si solar cell featuring a full-area SiO_(x)/MgO_(x)rear contact.

Polarization effects and tests for crystalline silicon solar cells

We try to find a fast and simple potential induced degradation effect （PID） test procedure for crystalline silicon solar cells. With sodium chloride （NaC1） solution as Na＋ source, PVB as lamination material, we can carry out the test in 1 h. Solar cells with newly developed PID resistance process were also tested. The increase of reverse current of solar cell can be considered a key standard to determine if the solar cell was prone to PID. Moreover, it showed that the increase of reverse current for the PID resistance solar cell was less than 2. In addition, the test results of the solar cells fitted very well with that of the modules by standard procedure.

Study of crystalline silicon solar cells with integrated bypass diodes

This paper reported a novel method of integrating bypass diodes into crystalline silicon solar cells.Bypass diodes which have the opposite p-n junction were formed by printing specific paste on the local surface of solar cells using screen printing,while infrared laser was applied to isolate the diode from the cell after firing.A module of crystalline silicon solar cells with integrated bypass diodes was fabricated and the I-V characteristics were measured under different shade conditions.The experimental results clearly showed that the integrated bypass diodes can effectively stabilize module's short circuit current while reduce the module power loss when shaded as well.

Progress of photovoltaic technology in China

Chinese government has been devoting itself to the development of renewable energy sources. This paper describes the history, achievement and future trends of photovoltaie technology, and suggestions axe proposed for strengthening the research and development （R＆D） ability of China.