We report the synthesis and photovoltaic properties of a ternary metal sulfide alloyed semiconductor Pb_xCd_1−xS prepared by the two‐stage sequential ionic layer adsorption reaction. The synthesized Pb_xCd_1−xS nanoparticles (NPs) retain the hexagonal structure of the CdS host with Pb substituting a fraction of the Cd atom (x = 0‐0.17). Band structures of Pb_xCd_1−xS with various Pb contents x were calculated using the complementary density functional theory (DFT) method. Optical, quantum efficiency, cyclic voltammetry measurements, and band structure calculation revealed that the band gap of Pb_xCd_1−xS decreased with increasing x, resulting in an increased optical absorption band from 500 to 720 nm (1.73‐2.44 eV) for x = 0 to 0.17. Solid‐state Pb_xCd_1−xS semiconductor nanoparticle‐sensitized solar cells (NSSCs) were fabricated from the synthesized NPs using spiro‐OMeTAD as the hole‐transporting material. The best Pb_0.05Cd_0.95S cell yielded a power conversion efficiency (PCE) of 3.67%, a V_oc of 0.70 V, and a fill factor (FF) of 62.8% under 1 sun. The PCE increased to 5.93% under a reduced light intensity of 0.1 sun and further increased to 8.48% under 0.01 sun. The external quantum efficiency (EQE) spectrum covers the spectral range of 300 to 730 nm with a maximal EQE of 82% at λ = 580 nm. The PCE over 8% can be categorized into a high‐efficiency NSSCs. In addition, the V_oc of 0.70 V is a relatively high V_oc among all NSSCs. The high PCE and V_oc suggest that Pb_xCd_1−xS has potential to be an efficient solar absorber.

中文翻译：

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带隙工程三元半导体PbxCd1-xS：在1％的阳光下效率为8.5％的纳米粒子敏化太阳能电池-结合理论和实验研究

我们报告了通过两步顺序离子层吸附反应制备的三元金属硫化物合金化半导体Pb _x Cd _{1 -x} S的合成和光电性能。合成的Pb _x Cd _{1 -x} S纳米颗粒（NPs）保留了CdS主体的六边形结构，其中Pb取代了一部分Cd原子（x = 0-0.17）。使用互补密度泛函理论（DFT）方法计算出具有各种Pb含量x的Pb _x Cd _{1 -x} S的能带结构。光学，量子效率，循环伏安法测量和能带结构计算表明，Pb的带隙_x Cd _{1 -x} S随着x的增加而减小，从而导致对于x = 0到0.17的光吸收带从500 nm增加到720 nm（1.73-2.44 eV）。固态Pb _x Cd _{1 -x} S半导体纳米粒子敏化太阳能电池（NSSCs）是使用spiro-OMeTAD作为空穴传输材料由合成的NP制成的。最好的Pb _0.05 Cd _0.95 S电池产生的功率转换效率（PCE）为3.67％， V _oc在1个阳光下的电压为0.70 V，填充因子（FF）为62.8％。在降低的0.1阳光下的光强度下，PCE增加到5.93％，在0.01阳光下进一步增加到8.48％。外部量子效率（EQE）光谱覆盖300至730 nm的光谱范围，在λ = 580 nm时最大EQE为82％。8％以上的PCE可以归类为高效NSSC。此外，在所有NSSC中，0.70 V的V _oc是一个相对较高的V _oc。高PCE和V _oc表明Pb _x Cd _{1 -x} S具有成为高效太阳能吸收剂的潜力。