Two-Stage Buffer Layers for Solar Power in a InGaP - Si Double Junction Cell

University Of Texas At Arlington, Arlington TX

Investigators

Abstract

Abstract Intellectual Merit The objective of this project is to monolithically integrate In0.50Ga0.50P on Si wafer substrates by using a thin nucleation layer of Ge followed by a metamorphic buffer comprised of step-graded InxGa1-xP. The thin 3 ML Ge layer will provide a nucleation template for the step-graded InxGa1-xP as well as provide a coherent, pseudomorphic interface at the top surface of the Si bottom p-n junction. We will be able to solve two key materials science issues together ? (i) provide nucleation for III-P semiconductors that normally do not interface well directly with Si atoms and (ii) provide a clean interfacial layer that can electrically passivate the n-type Si emitter layer of the Si bottom p-n junction. Broader Impact The National Academy of Engineering selected the top 14 engineering challenges for the 21st century facing humanity worldwide. Challenge #1 - "Make Solar Energy Economical? by ?overcoming the barriers to widespread solar power generation." Our project provides a way to address this societal grand challenge by demonstrating a two stage metamorphic buffer designed to monolithically integrate In0.50Ga0.50P and Si, despite lattice mismatch, into an efficient, affordable and nontoxic solar cell. Two graduate students will be engaged in semiconductor material characterization and epitaxial thin film synthesis. In addition, we will select a K-12 teacher from a local Independent School District to participate in a 6-week summer program. This program will focus on engaging the teacher with our research and the subsequent development of classroom materials for teaching future scientists, engineers, and technologists.