Role of bulk- and interface-defects in spectrum-dependent energy harvesting of CZTSSe-based indoor photovoltaic devices

In this work, we theoretically investigate spectrum dependent energy harvesting of a thin-film indoor photovoltaic (PV) device, taking into account the role of defects. By numerically solving Poisson’s equation and the continuity equation under optical generation-recombination conditions, performance characteristics of a Cu2ZnSn(S,Se)4-based thin-film PV device have been evaluated under spectrally varying white light emitting diodes (LEDs). Without any loss of generality, the results of the experimentally validated theoretical model suggest that a thin-film PV device becomes significantly tolerant to both bulk and interface defects when a fraction of blue emission in the white LED spectra remains relatively low. For a white LED having cool white emission characteristics, the efficiency of a CZTSSe-based PV device can equal the efficiency of the…