Dependence of InGaN solar cell performance on polarization-induced electric field and carrier lifetime

• Published in: Chinese physics B Vol. 22; no. 9; pp. 671 - 675
• Main Author: 杨静 赵德刚 江德生 刘宗顺 陈平 李亮 吴亮亮 乐伶聪 李晓静 何晓光 王辉 朱建军 张书明 张宝顺 杨辉
• Format: Journal Article
• Language: English
• Published: 01.09.2013
• Subjects: Carrier lifetime; Density; Doping; Electric fields; Indium gallium nitrides; InGaN; Photovoltaic cells; Polarization; Short circuit currents; Solar cells; 光电性能; 压电极化; 太阳能电池; 掺杂浓度; 电场诱导; 短路电流密度; 载流子寿命
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/22/9/098801

The effects of Mg-induced net acceptor doping concentration and carrier lifetime on the performance of a p-i-n InGaN solar cell are investigated. It is found that the electric field induced by spontaneous and piezoelectric polariza- tion in the i-region could be totally shielded when the Mg-induced net acceptor doping concentration is sufficiently high. The polarization-induced potential barriers are reduced and the short circuit current density is remarkably increased from 0.21 mA/cm2 to 0.95 mA/cm2 by elevating the Mg doping concentration. The carrier lifetime determined by defect density of i-InGaN also plays an important role in determining the photovoltaic properties of solar cell. The short circuit current density severely degrades, and the performance of InGaN solar cell becomes more sensitive to the polarization when carrier lifetime is lower than the transit time. This study demonstrates that the crystal quality of InGaN absorption layer is one of the most important challenges in realizing high efficiency InGaN solar cells.