A Novel Fabrication Process for Polysilicon Thin Film Solar Cells

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

This grant provides funding for the detailed study of a novel thin-film silicon solar cell fabrication process that uses significantly less energy than current processes. The silicon will be delivered via a low temperature deposition onto a metal layer; the stack will then be crystallized in the solid phase using a novel pulsed rapid thermal annealing process. This study includes an in-depth investigation of the fundamental process-structure relationship that influences the solar cell performance. The experimental study will elucidate the crystallization mechanism by exploring the effects of crystallization rate, concentration profile and grain structure. Optimization of the multi-layer polycrystalline structure and properties will be a goal of the study as well. Although the primary focus is on the single-junction solar cell structure, multiple-junction cells will be fabricated using the same kind of process. Commercial low-temperature glass will be used as the substrate for the solar cell fabrication. If successful, the result of this research will provide a viable solution to the photovoltaic industry, i.e., a low-cost mass production process on the large-area glass substrate with high throughput. The primary goal of this work is to understand the key process factors that affect the bulk and interface polycrystalline thin-film structure and material properties for optimum solar cell performance. The same principle is applicable to the fabrication of a wide range of polycrystalline semiconductor thin films for solar cells and other nano- and micro-electronic devices. This work will also contribute to the advancement of solid-state material science, device fabrication, and rapid thermal annealing processes.