Photovoltaic device formed on porous silicon isolation

US8829332B1 · kind B1 · utility

Assignees

• TOWER PARTNERS SEMICONDUCTOR CO., LTD. · IL
• YISSUM RESEARCH DEVELOPMENT COMPANY OF THE HEBREW UNIVERSITY OF JERUSALEM LTD. · IL

Inventors

• Yakov Roizin · Afula, IL
• Evgeny Pikhay · Haifa, IL
• Irit Chen-Zamero · Haifa, IL
• Ora Eli · Afula, IL
• Micha Asscher · Jerusalem, IL
• Amir Saar · Jerusalem, IL

Key dates

• Filing date: Mar 14, 2013
• Grant date: Sep 9, 2014
• Expiry date: Mar 14, 2033

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50

Abstract

A photovoltaic device includes lateral P-I-N light-sensitive diodes disposed on a silicon island formed by a P− epitaxial layer and surrounded by trenches that provide lateral isolation, where the island is separated from the substrate by a porous silicon region that is grown under the island and isolates the lower portions of the photovoltaic device from the highly doped substrate. The trenches extend through the P− epitaxial material into the P+ substrate to facilitate self-limiting porous silicon formation at the bottom of the island, and also to suppress electron-hole recombination. A protective layer (e.g., SiN) is formed on the trench walls to further restrict porous silicon formation to the bottom of the island. Black silicon on the trench walls enhances light capture. The photovoltaic devices form low-cost embedded photovoltaic arrays on CMOS IC devices, or are separated to produce low-cost, HV solar arrays for solar energy sources, e.g. for solar concentrators.