Das Aparajita, Deepa Melepurath, Ghosal Partha
Department of Chemistry, Indian Institute of Technology Hyderabad Kandi-502285 Sangareddy Telangana India
Defence Metallurgical Research Laboratory DRDO Hyderabad 500058 Telangana India.
RSC Adv. 2018 Oct 12;8(61):34984-34998. doi: 10.1039/c8ra04956d. eCollection 2018 Oct 10.
Quantum dot solar cells (QDSCs) with hexagonal fullerene nanosheets (C-NS) embedded in a titanium oxide/cadmium sulfide (TiO/CdS) photoanode coupled with a carbon-cloth (C-cloth) coated with molybdenum sulfide (MoS) counter electrode (CE) are studied for the first time. C-NS due to a favorable work function of 4.57 eV and a conductance of 1.44 μS, enable faster electron injection from the conduction band of cadmium sulfide to the current collector, in contrast to the bulk fullerene based TiO/CdS solar cell. The champion cell with the TiO/C-NS/CdS photoanode and a MoS/C-cloth CE exhibits a high power conversion efficiency of 5.6%, greater by ∼14% relative to its' analogue cell with bulk fullerene. A large area cell of 1 cm dimensions with TiO/C-NS/CdS gives a PCE of 2.9%. The effect of MoS in improving the efficiency of the cell with a TiO/C-NS/CdS photoanode is realized in terms of enhanced electrocatalytic activity for polysulfide reduction, and lower charge transfer resistance at the polysulfide/CE interface compared to a cell with the same photoanode but having pristine carbon-cloth as the CE. The ability of MoS for catalyzing the oxidized polysulfide species at the CE and C-NS for improving the charge collection at the photoanode serve as indicators for their wider utilization in solar cells. It also serves as a good supercapacitor material. A MoS/C-cloth based symmetric cell exhibits a specific capacitance of 645 F g at 2 A g, which shows its' potential for energy storage as well. By integrating the QDSC and the supercapacitor, the resulting integrated device acquires a photovoltage of 0.7 V, under 1 sun illumination.
首次研究了一种量子点太阳能电池（QDSC），其氧化钛/硫化镉（TiO/CdS）光阳极中嵌入了六方富勒烯纳米片（C-NS），并与涂有硫化钼（MoS）的碳布（C-cloth）对电极（CE）耦合。与基于块状富勒烯的TiO/CdS太阳能电池相比，C-NS具有4.57 eV的良好功函数和1.44 μS的电导率，能够使电子从硫化镉的导带更快地注入到集流体中。具有TiO/C-NS/CdS光阳极和MoS/C-cloth CE的最佳电池表现出5.6%的高功率转换效率，相对于其块状富勒烯类似电池提高了约14%。尺寸为1 cm的大面积TiO/C-NS/CdS电池的光电转换效率为2.9%。MoS对具有TiO/C-NS/CdS光阳极的电池效率的提升作用体现在增强了对多硫化物还原的电催化活性，并且与具有相同光阳极但以原始碳布作为CE的电池相比，在多硫化物/CE界面处的电荷转移电阻更低。MoS在CE处催化氧化多硫化物物种以及C-NS改善光阳极电荷收集的能力，表明它们在太阳能电池中有更广泛的应用潜力。它也是一种良好的超级电容器材料。基于MoS/C-cloth的对称电池在2 A g下表现出645 F g的比电容，这也显示了其储能潜力。通过集成QDSC和超级电容器，所得集成器件在1个太阳光照下获得了0.7 V的光电压。
