根据第一层材料禁带宽度与第二层材料禁带宽度，绘制不同损失率下，两种材料禁带宽度随损失率变化的关系曲线以及双层材料光伏转换极限效率曲线-According to the first layer of material with a band gap of the material the band gap of the second layer, draw a different loss rate curves of the two materials with the band gap of the rate of change and the loss of bilayer material photovoltaic conversion efficiency curve limit