Lee Su-Hwan, Kim Dal-Ho, Shim Tae-Hun, Park Jea-Gun
Nano-SOI Process Laboratory, Hanyang University, 17 Haengdang-Dong, Seongdong-Gu, Seoul 133-791, Republic of Korea.
Nanotechnology. 2009 Aug 19;20(33):335201. doi: 10.1088/0957-4484/20/33/335201. Epub 2009 Jul 28.
In organic photovoltaic (OPV) devices fabricated with a double small-molecular layer, the power conversion efficiency strongly depends on the thickness of the organic donor layer (here, copper phthalocyanine). In other words, the power conversion efficiency increases with the donor layer thickness up to a specific thickness ( approximately 12.7 nm) and then decreases beyond that thickness. This trend is associated with the light absorption and carrier transport resistance of the small-molecular donor layer, both of which strongly depend on the layer thickness. Experimental and calculated results showed that the short-circuit current due to light absorption increased with the donor layer thickness, while that due to current through the donor layer decreased with 1/R. Since the total short-circuit current is the product of the light absorption current and current through the donor layer, there is a trade-off, and the maximum power conversion efficiency occurs at a specific organic donor layer thickness (e.g. approximately 12.7 nm in this experiment).
在采用双小分子层制造的有机光伏（OPV）器件中，功率转换效率强烈依赖于有机供体层（此处为铜酞菁）的厚度。换句话说，功率转换效率随着供体层厚度增加，直至达到特定厚度（约12.7纳米），然后在超过该厚度时下降。这种趋势与小分子供体层的光吸收和载流子传输电阻相关，这两者都强烈依赖于层厚度。实验和计算结果表明，由于光吸收产生的短路电流随着供体层厚度增加，而通过供体层的电流产生的短路电流随1/R下降。由于总短路电流是光吸收电流和通过供体层电流的乘积，存在一种权衡，并且最大功率转换效率出现在特定的有机供体层厚度处（例如本实验中约12.7纳米）。
