Kesterite tech news
On October 21, 2026, researchers from the University of Oxford and Universitat Politècnica de Catalunya published a strategic perspective in Applied Physics Letters outlining a commercial pathway for earth--abundant kesterite (${\text{Cu}}_2{\text{ZnSnS}}4$ / CZTS / CZTSSe) indoor photovoltaics (IPVs) to power autonomous Internet of Things (IoT) devices and low--power smart sensors. Addressing toxicity and supply constraints inherent in lead--halide perovskite and III--V indoor harvesters, the authors demonstrated that tuning kesterite's bandgap toward approximately 1.9 eV enables optimal spectral matching with indoor LED and fluorescent illumination. To transition kesterite IPVs from laboratory scale to industrial production, the study details mitigation strategies for shunt resistance ($R{\text{sh}}$) leakage and non--radiative recombination under low--light intensities, while validating the substitution of hazardous cadmium sulfide (CdS) buffer layers with environmentally benign zinc oxysulfide (Zn(O,S)) and zinc tin oxide (ZTO) thin films.