Browse Prior Art Database

Chemically Passive, Electrically Active Films for Photolytic Structures

IP.com Disclosure Number: IPCOM000087004D
Original Publication Date: 1976-Nov-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR [+4]

Abstract

Semiconductors most effective in collecting solar energy also tend to decompose in solutions used for photolysis. Previously, it has been found that H(2) and O(2) can be formed by photolysis using an electrolytic solution, a Pt electrode, and a semiconducting metal-oxide electrode such as TiO(2) and SrTiO(3). These materials efficiently generate H(2) and O(2) and, also, are chemically stable in the electrolytic solutions during photolysis. However, the efficiency of photolysis using solar energy is quite low, since the band gaps of these materials are greater than 3eV. It has also been found that when lower band gap n-type semiconductors, such as Si and GaAs, are used as the O(2) electrode, they will decompose into the solution.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 75% of the total text.

Page 1 of 1

Chemically Passive, Electrically Active Films for Photolytic Structures

Semiconductors most effective in collecting solar energy also tend to decompose in solutions used for photolysis. Previously, it has been found that H(2) and O(2) can be formed by photolysis using an electrolytic solution, a Pt electrode, and a semiconducting metal-oxide electrode such as TiO(2) and SrTiO(3). These materials efficiently generate H(2) and O(2) and, also, are chemically stable in the electrolytic solutions during photolysis. However, the efficiency of photolysis using solar energy is quite low, since the band gaps of these materials are greater than 3eV. It has also been found that when lower band gap n-type semiconductors, such as Si and GaAs, are used as the O(2) electrode, they will decompose into the solution.

A structure is described for efficiently generating O(2) and H(2) via photolysis using solar energy which comprises the following solution for the difficulties described above of prior photolytic structures. An n-type semiconductor material with a band gap > 1.23 eV and a work function < 4.5 eV, covered with a film which is:

(a) chemically inert, transparent to solar energy, during photolysis, and thin enough for photo-excited holes generated in the semiconductor to tunnel through to generate O(2); or

(b) chemically inert during photolysis, transparent to solar energy and with a band gap structure such that the valance band or interband states of the film lie at energ...