Browse Prior Art Database

Efficient Visible Luminescence from Hydrogenated Amorphous Silicon

IP.com Disclosure Number: IPCOM000051195D
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Plecenik, RM: AUTHOR [+4]

Abstract

We report efficient broadband visible photoluminescence in a-Si:H films, i.e., amorphous SiH(x) (0.2 < x < 0.5) prepared by homogeneous chemical vapor deposition (HOMOCVD). For growth temperatures, T(s), from 200-500 degrees C, an optical gap approx. 1.6 eV obtains, and typical 1.4 eV a-Si:H luminescence is observed at 5 degrees K. For growth below 200 degrees C, the gap increases sharply with decreasing T(s) and new 0.35 eV-wide emission develops, shifting to higher energies with the gap. In room temperature deposited films, the gap reaches 2.6 eV and emission peaks near 1.99 eV. Occurrence of this new band correlates with large hydrogen incorporation (20-50 at.%.), low EPR spin density (< 4x10/16/ cm/-3/ ), large optical gap (1.6-2.6 eV) and polysilane chain formation.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Efficient Visible Luminescence from Hydrogenated Amorphous Silicon

We report efficient broadband visible photoluminescence in a-Si:H films, i.e., amorphous SiH(x) (0.2 < x < 0.5) prepared by homogeneous chemical vapor deposition (HOMOCVD). For growth temperatures, T(s), from 200-500 degrees C, an optical gap approx. 1.6 eV obtains, and typical 1.4 eV a-Si:H luminescence is observed at 5 degrees K. For growth below 200 degrees C, the gap increases sharply with decreasing T(s) and new 0.35 eV-wide emission develops, shifting to higher energies with the gap. In room temperature deposited films, the gap reaches 2.6 eV and emission peaks near 1.99 eV. Occurrence of this new band correlates with large hydrogen incorporation (20-50 at.%.), low EPR spin density (< 4x10/16/ cm/-3/ ), large optical gap (1.6-2.6 eV) and polysilane chain formation. We find 1 percent efficient visible luminescence persisting at room temperature. Similar results are obtained if the a-Si:H films are prepared using HOMOCVD or RF plasma decomposition (T(s) < 200 degrees C) of higher silanes; however, not with plasma decomposition of monosilane. These materials may find applications as photoluminescent and electroluminescent displays when prepared by doping and forming p-i-n, p-n or Schottky barrier junctions.

1