Method of forming light-trapping surface for photovoltaic cell and resulting structure
US4918030A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1989 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Mar 31, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/50
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved textured surface of a photovoltaic device is provided by an anisotropic etching process in which pyramidal structures are formed on a silicon surface having a (100) crystallographic orientation. An aqueous solution of an alkali metal hydroxide is heated to approximately 85.degree. C. whereupon isopropyl alcohol is added. Separated silicon wafers are immersed in the solution for approximately 45 minutes. The wafers can be agitated for a limited time in the solution, and preferably the wafers and solution are covered during the etching step. The resulting pyramids are on the order of 14 microns high and 20 microns on each side of the base. The overlap of the pyramids provides desired random locations for the pyramids.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.