Quantum dot-sensitized solar cells (QDSCs) present promising cost-effective alternatives to conventional silicon solar cells due to their distinctive properties such as simplicity in fabrication, possibility to realize light absorption in wide solar spectrum regions, and theoretical conversion efficiency up to 44%. This review highlights recent developments in critical materials including quantum dots, photoanodes, counter electrodes (CEs), and electrolytes for QDSC applications. Among them, electron recombination at the photoanode/electrolyte interface limits the evolution of high-efficiency QDSCs, therefore the optimized construction of quantum dots, the various microtopographies of wide bandgap semiconductors (TiO₂, ZnO) as well as emerging CEs having good electrocatalytic activity are elaborated in this paper. We argue that these key factors can provide design guidelines for future successful applications and significantly promote the development of QDSCs. Liquid, quasi-solid-state, and solid-state electrolytes for QDSCs are summarized, aiming at enhancing the long-term stability of QDSCs. This review presented below gives a succinct summary of materials for QDSC applications, with a conclusion and future prospects section.

In the current work, we report a series of bifacial dye-sensitized solar cells (DSSCs) that provide power conversion efficiencies of more than 10% from bifacial irradiation. The device comprises an N719-sensitized TiO₂ anode, a transparent nickel selenide (Ni–Se) alloy counter electrode (CE), and liquid electrolyte containing I⁻/I₃ ⁻ redox couples. Because of the high optical transparency, electron conduction ability, electrocatalytic activity of Ni–Se CEs, as well as dye illumination, electron excitation and power conversion efficiency have been remarkably enhanced. Results indicate that incident light from a transparent CE has a compensation effect to the light from the anode. The impressive efficiency along with simple preparation of the cost-effective Ni–Se alloy CEs highlights the potential application of bifacial illumination technique in robust DSSCs.