• LIPING CHEN

Articles written in Bulletin of Materials Science

• Study on the improvement of p-type multi-crystalline silicon material for solar cells by the hydrogenation with electron injection

In this paper, we have found that the efficiency of p-type mono-crystalline silicon (mono-Si) passivated emitter and rear contact (PERC) solar cells can be increased by 0.12%abs. with the process of hydrogenation with electron injection(HEI). However, the same scheme was not suitable for p-type multi-crystalline silicon (mc-Si) solar cells. To promote power conversion efficiency (PCE) for the mc-Si solar cells, we have explored a developed HEI process for the mc-Si solar cells to improve the device performance. Meanwhile, we also analysed the mechanization inside the solar cells after applying the HEI process. Through the design of experiment (DOE), the correlation among injection current, temperature, injection time and efficiency improvement was analysed in detail. It was proved that mc-Si solar cells require higher current injection andtemperature to passivate the complex impurities in the bulk, when compared to mono-Si solar cells.With the optimal scheme explored by this paper, the open circuit voltage (Uoc), short circuit current density (Jsc) and fill factor (FF) of p-type mc-Si solar cells, respectively, increased by 1.2 mV, 0.11 mA cm$^{−2}$ and 0.05% abs., respectively. The efficiency was improved about $0.11\pm 0.005$% abs.. These results will provide a certain method and basis for further improving the efficiency of mc-Si PERC cells and overcoming the light-elevated temperature-induced degradation by HEI process.

• Accelerated potential-induced degradation technology for crystalline silicon cells

Potential-induced degradation (PID) is recently recognized as one of the most important degradation mechanisms in crystalline silicon cells as well as in photovoltaic (PV) modules. The ability of solar cells to resist PID effect is one of the key indicators of product quality monitoring. Traditional PID testing methods are complex and require up to 96 h in treating. To accelerate the PID test, a rapid PID treatment technology was urgent for PV field, which can extremely decrease the time expense. Hence, we have introduced a novel rapid PID treating technology, which reduced the treatment time from nearly 100 h to less than 8 h. This technology was applying an electric field directly on the solar cells to simulate the PID process of the modules. The process was named as electric field treatment (EFT). The effect of the applied EFT voltage on the solar cells was investigated from 1 to 1.8 KV. The degradation rate of the solar cells increased with increase in EFT voltage. The result of the energy dispersive spectrometer showed that the sodium element was found in the shunt area of the cell. It indicated that the microscopic principle of the power loss of the cell caused by the EFT was in accordance with that of the traditional PID. The electric performances of the cells treated by EFT showed that the PID test time can be accelerated to less than 8 h.

• # Bulletin of Materials Science

Volume 45, 2022
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020