新型MIp~+-Al_(0.3)Ga_(0.7)As/p-n-n~+-GaAs太阳电池的设计与I-V特性理论分析

为充分利用太阳光的短波部分,将AlxGa1-xAs设计为电池的又一个光伏工作层,并引入固定负电荷,建立界面感应势垒,形成MIp -AlGaAs感应结,有效降低界面对光生电子的复合。以制作工艺简单的p -AlGaAs／p-GaAs界面,将感应结与p／n-GaAs部分连接起来,构成新型高效率复合结构MIp -Al0.3Ga0.7As／p-n-n -GaAs太阳电池。其I-V特性理论研究绐果表明,选择合适的负电荷面密度数和Al0.3Ga0.7As层的掺杂浓度,即:建立合适高度的感应势垒,可显著降低界面复合速度近8个数量级。优化设计得到的整个电池的效率为31.5％,较传统的窗口层电池有明显提高。

A NOVEL MIp+-AlGaAs/p-n-n+-GaAs SOLAR CELL: DESIGN AND THEORETIC INVESTIGATION FOR I-V CHARACTERISTICS

To make good use the high energy of solar energy, AlxGa1-xAs was designed to be a added wok layer, and fixed negative charges were introduced on the interface of MIp-AlxGa1-xAs, and the induced potential on interface was established as well, which would result in the formation of MIp -AlGaAs induced junction and effective diminishment of interface recombination. Then the novel MIp -Al0.3Ga0.7As/p-n-n -GaAs cell with high efficiency was designed successfully, where the induced junction and p/n GaAs junction would be linked easily by p -AlGaAs/p-GaAs interface. The theoretic investigation of I-V characteristics showed that, choosing suitable values of the area density of fixed negative charges and the doping concentration of p-AlGaAs, namely establishing with proper height, the recombination velocity on the interface would be decreased remarkably by eight orders approximately. To be a conclusion, the efficiency of cell with optimized structure would be 31.5%, which is obviously higher than those of GaAs cells with traditional structure.