Synthesis of AgInS2 quantum dots with tunable photoluminescence for sensitized solar cells

Abstract

Abstract Synthesis of quantum dots (QDs) with high photoluminescence is critical for quantum dot sensitized solar cells (QDSCs). A series of high quality AgInS 2 QDs were synthesized under air circumstance by the organometallic high temperature method. Feature of tunable photoluminescence of AgInS 2 QDs with long lifetime and quantum yields beyond 40% has been achieved, which was mainly attributed to the donor-acceptor pair recombination, contributed above 91% to the whole emission profiles. After ligand exchange with bifunctional linker, water-soluble AgInS 2 QDs were adopted as light harvesters to fabricate QDSCs, achieved best PCE of 2.91% (short-circuit current density of 13.78 mA cm −2 , open-circuit voltage of 0.47 V, and fill factor of 45%) under one full sun illumination. The improved photovoltaic performance of AgInS 2 QDs-based QDSCs is mainly originated from broadened optoelectronic response range up to ∼900 nm, and enhanced photoluminescence with long lifetime and high quantum yield beyond 40%, which provide strong photoresponse ∼40% over the window below 750 nm. The synthetic approach combined with intrinsic defects created by intentionally composition modulation introduces a new approach towards the goal of high performance QDSCs.