Tuning the Optical Properties of Quantum Dots to Increase the Efficiency of Solar Cells

Abstract

Quantum Dot Solar Cells (QDSC) are a promising class of third-generation solar cells that are being developed to deliver pathbreaking efficiencies as a result of the unique optical properties of quantum dots, and this paper aims to increase their currently dismaying efficiency. Based on the size-based tunability of quantum dot band gaps, a model is developed that relies on absorbing a larger span of energies for photons to efficiently convert them to excitons. By considering a set of binary compounds used as semiconductor materials in quantum dots and processing them through mathematical equations derived from Schrödinger's equation for an electron in an infinite potential well, a final group of candidates in a range of sizes are selected based on their wavelength absorption ranges and coverage of the solar spectrum. These quantum dot candidates are then finalized considering material characterizations and are arranged in a photovoltaic cell to generate maximum efficiency. A layer-by-layer process is discussed for deposition, while a method of effective size distribution is proposed. An analysis of energy losses including electron recombination and surface defects are further discussed, and solutions are proposed. The end product is a framework for highly efficient quantum dot structures within a QDSC that can be employed commercially.