Amorphous silicon solar cells prepared at high deposition rates. Annual subcontract report, July 1, 1989-June 30, 1990.

摘要

This document describes the progress in the research of amorphous silicon solar cells prepared at high deposition rates. By using high excitation frequency (110 MHz) and optimization of deposition conditions, the electronic properties of i-layers deposited from Si(sub 2)H(sub 6) or SiH(sub 4) at approximately 2 nm/s approached the properties of low deposition rate films. B(CH(sub 3))(sub 3) was used as an alternative p-layer doping gas. The results show that B(CH(sub 3))(sub 3) is a better doping gas than B(sub 2)H(sub 6), due to its better thermal stability and produces a film with better electro-optical properties. The open-circuit voltage, V(sub oc), of the devices has been improved by using a B(CH(sub 3))(sub 3) p-layer and a better p/i interface layer. The short circuit current density, J(sub sc), has been improved by using an ITO/Ag back reflector. The key for fabricating high-deposition-rate SiH(sub 4) devices has been found to be the p/i interface. As a result, high-deposition-rate cells deposited from both Si(sub 2)H(sub 6) and SiH(sub 4) source gases reached 10% efficiencies. A 1-cm(sup 2) cell deposited at 2 nm/s from Si(sub 2)H(sub 6) reached 10.1% initial efficiency as measured by the Solar Energy Research Institute. 16 refs., 11 figs., 3 tabs.