Inorganic Material: WSe₂ as a Hole Transport Material for Perovskite Solar Cells

S. Aryal, A.B. Kaul
University of North Texas,
United States

Keywords: WSe₂, TMDCs, Perovskite, solar cell, hole transport material, IoT, stability

Summary:

Addressing the growing need for sustainable and clean energy in today's world of pervasive Internet of Things (IoT) is crucial. And the employment of renewable and environmentally friendly energy sources is imperative. Solar power, as a sustainable energy alternative, not only holds the potential to significantly impel the expansion of low-powered electronics but also to meet the urging high green energy demand. In simultaneous time, Perovskite solar cells have garnered significant interest within the PV community due to the escalating power conversion efficiency, surpassing an efficiency level of 25% and the advantage of cost-effective solution processing. Replacing the spiro-OMeTAD with low-cost inorganic hole transport materials (HTMs) are important avenues to enhance stability of the perovskite’s solar cells and the appeal for potential commercialization in the advancement of Internet of Things. In pursuit of enhancing the environmental stability of perovskite solar cells (PSCs), the exploration of cost-effective solution-exfoliated two-dimensional (2D) transition metal dichalcogenides, such as WSe₂, emerges as a compelling strategy. Our study focuses on utilization of perovskite compatible solution exfoliated WSe₂ as a hole transport material in solar cells. We characterized the exfoliation of WSe₂ based on Raman spectroscopy and UV-Vis spectroscopy and performed IV characterization on the WSe₂ film. Using Photoluminescence (PL) spectroscopy, we compared the contribution of the both hole transport material - spiro-OMeTAD and WSe₂ - when it is atop the perovskite film. We finally fabricated the n-i-p architecture solar cells and compared the stability of the solar cells when exposed to moisture. In addition, forming an array of solar cells we performed a prototypical demonstration by illuminating a low-power LED, opening the avenues to incorporate the usage of solar cells in IoT.