High efficiency photovoltaics through engineering spontaneous emission

University Of Maryland, College Park, College Park MD

Investigators

Abstract

PI: Munday, Jeremy Proposal Number: 1335857 Institution: University of Maryland College Park Title: High efficiency photovoltaics through engineering spontaneous emission The objective of this project is to show that the suppression of the spontaneous emission rate of a solar cell leads to an improvement in the cell?s efficiency. The inhibition of spontaneous emission leads to increased carrier concentrations and hence an increase in the quasi-Fermi level splitting and cell voltage. To suppress the spontaneous emission rate, photonic crystals will be used, which are well known to decrease the radiative rate of recombining carriers. This effect will lead to higher open circuit voltages and hence higher cell efficiencies. Over the past two decades, much work has been done in the two separate fields of spontaneous emission engineering and in photovoltaics. This proposal represents the convergence of these fields, which may have a transformative impact on photovoltaic devices by adding an additional degree of freedom to the design: spontaneous emission engineering. Photonic crystals are known to inhibit spontaneous emission, which leads to an increase in the carrier lifetime. By increasing the free carrier lifetime, and hence the density of free carriers, the quasi-Fermi level splitting increases, leading to an improvement in the open circuit voltage. In this project, photonic crystal solar cells will be developed to suppress spontaneous emission and improve solar cell power conversion efficiencies. In addition to the societal benefits of improving clean energy generation technologies, the PIs will engage in a number of activities aimed to encourage future scientists, educate the public, and disseminate new finding to the scientific community. These activities include recruitment of under-represented groups through the Louis Stokes Alliance for Minority Participation Undergraduate Research Program (LSAMP URP) at the University of Maryland, the Undergraduate Summer Research Program within the Institute for Research in Electronics and Applied Physics, and outreach to local high schools by encouraging and supporting high school students to perform research projects in their labs.