Yoo Beomjin, Kim Kang-Jin, Lee Doh-Kwon, Kim Kyungkon, Ko Min Jae, Kim Yong Hyun, Kim Won Mok, Park Nam-Gyu
Solar Cell Center, Korea Institute of Science and Technology, Seoul, Korea.
Opt Express. 2010 Sep 13;18 Suppl 3:A395-402. doi: 10.1364/OE.18.00A395.
We prepared a back-contact dye-sensitized solar cell and investigated effect of the sputter deposited thin TiO₂ film on the back-contact ITO electrode on photovoltaic property. The nanocrystalline TiO₂ layer with thickness of about 11 μm formed on a plain glass substrate in the back-contact structure showed higher optical transmittance than that formed on an ITO-coated glass substrate, which led to an improved photocurrent density by about 6.3%. However, photovoltage was found to decrease from 817 mV to 773 mV. The photovoltage recovered after deposition of a 35 nm-thick thin TiO₂ film on the surface of the back-contact ITO electrode. Little difference in time constant for electron transport was found for the back-contact ITO electrodes with and without the sputter deposited thin TiO₂ film. Whereas, time constant for charge recombination increased after introduction of the thin TiO₂ film, indicating that such a thin TiO₂ film protected back electron transfer, associated with the recovery of photovoltage. As the result of the improved photocurrent density without deterioration of photovoltage, the back-contact dye-sensitized solar cell exhibited 13.6% higher efficiency than the ITO-coated glass substrate-based dye-sensitized solar cell.
我们制备了一种背接触式染料敏化太阳能电池，并研究了溅射沉积在背接触式ITO电极上的TiO₂薄膜对光伏性能的影响。在背接触结构的普通玻璃基板上形成的厚度约为11μm的纳米晶TiO₂层，其光学透过率高于在ITO涂层玻璃基板上形成的纳米晶TiO₂层，这使得光电流密度提高了约6.3%。然而，发现光电压从817mV降至773mV。在背接触式ITO电极表面沉积35nm厚的TiO₂薄膜后，光电压得以恢复。对于有和没有溅射沉积TiO₂薄膜的背接触式ITO电极，发现电子传输的时间常数差异不大。然而，引入TiO₂薄膜后，电荷复合的时间常数增加，这表明这种TiO₂薄膜保护了背向电子转移，与光电压的恢复有关。由于光电流密度提高而光电压没有恶化，背接触式染料敏化太阳能电池的效率比基于ITO涂层玻璃基板的染料敏化太阳能电池高13.6%。
