SnS掺杂对P3HT/PCBM体系太阳能电池光电特性的影响研究

采用连续离子层吸附反应法(SILAR)在TiO₂/FTO电极上沉积SnS, 组装结构为FTO/TiO₂/SnS/ P3HT:PCBM/Ag的多层异质结太阳能电池, 结果显示: SnS掺杂能显著提高P3HT/PCBM体系太阳能电池的光电转化性能。通过SEM观察、UV-Vis光谱、J-V曲线、Raman光谱以及射频辉光放电光谱仪(GD-OES)等手段, 系统研究了不同前驱体液浓度制备的SnS对电池的影响, 发现当n(Sn²⁺):n(S^2-)为1:1.5时, 电池的光电转化效率最高, 达到0.369%, 其开路电压、短路电流和填充因子分别达到0.373 V、1.92 mA/cm²和51.2%。另外, GD-OES谱图显示前驱体溶液中Sn²⁺/S^2-比例对于SnS_x层的化学组成及沉淀量具有重要影响, 从而导致复合太阳能电池光电性能的显著变化。

Effects of SnS Doping on Photovoltaic Performance of P3HT:PCBM Multilayer Heterojunction Solar Cells

SnS was deposited on the surface of FTO/TiO₂ electrodes with different molar concentration ratio of Sn²⁺ and S^2- using successive ionic layer absorption and reaction (SILAR) method. Afterwards, the as-prepared TiO₂/SnS composite electrode was assembled into a multilayer heterojunction solar cell with an architecture of FTO/TiO₂/SnS/ P3HT:PCBM/Ag. The TiO₂/SnS composite films were characterized by scanning electron microscopy (SEM), Raman spectra analysis and Glow discharge optical emission spectrometer (GD-OES). The photovoltaic performance of solar cells were determined using UV-Vis spectra and I-V curves. Results showed that incorporation of SnS significantly improved the short-circuit current of the multilayer heterojunction solar cells. Meanwhile, the dependence of the photovoltaic performance of solar cells on the molar concentration ratio of Sn²⁺/S^2- was investigated systematically. During the SILAR processes, a series of electrodes were prepared in the precusor solutions with different Sn²⁺/S^2- molar concentration ratios (n(Sn²⁺):n(S^2-)= 1:1, 1:1.25, 1:1.5, 1:1.75 and 1:2). Moreover, GD-OES method distinguished the effects of Sn²⁺/S^2- ratio on the SnS_x layer deposition. It was found that the Sn²⁺/S^2- ratio of SILAR precursors, dominated by thickness and chemical composition of SnS_x, affected photovoltaic performance of the solar cells significantly. I-V test results testified that the ratio of Sn²⁺/S^2- molar concentration was optimized at 1:1.5, which resulted in the highest photoelectric conversion efficiency. The open-circuit voltage (V_oc), short-circuit current density (J_sc), fill factor (FF), and power conversion efficiency (PCE) reached 0.373 V, 1.92 mA/cm², 51.2%, and 0.369%, respectively.