Enhancing broadband emission in indirect bandgap lead halide perovskites by hydrostatic pressure

Although broadband emission caused by self-trapped excitons (STE) has been widely studied in direct bandgap perovskites, few attention has been paid to indirect bandgap perovskites. Here we report that indirect bandgap all-inorganic perovskite exhibits typical STE induced broadband emission. We use diamond anvil cell to study the response of optical properties of 2D perovskite microplates to hydrostatic pressure. The broadband emission intensity increases significantly with increasing pressure, and the peak position is largely blue-shifted by 650 meV. The mechanism of these phenomena is discussed using experimental methods and theoretical calculations. This work shows a potential method to control and utilize indirect bandgap perovskites materials in optoelectronic devices. <div id="gtx-trans" style="position: absolute; left: 169px; top: 60.04px;"> <div class="gtx-trans-icon"> </div> </div>