Improved Conversion Efficiency of GaN/InGaN Thin-Film Solar Cells

Author

Horng, Ray-Hua ; Lin, Shih-Ting ; Tsai, Yu-Li ; Chu, Mu-Tao ; Liao, Wen-Yih ; Wu, Ming-Hsien ; Lin, Ray-Ming ; Lu, Yuan-Chieh

Author_Institution

Inst. of Precision Eng., Nat. Chung Hsing Univ., Taichung

Volume

30

Issue

7

fYear

2009

fDate

7/1/2009 12:00:00 AM

Firstpage

724

Lastpage

726

Abstract

In this letter, we report on the fabrication and photovoltaic characteristics of p-i-n GaN/InGaN thin-film solar cells. The thin-film solar cells were fabricated by removing sapphire using a laser lift-off technique and, then, transferring the remaining p-i-n structure onto a Ti/Ag mirror-coated Si substrate via wafer bonding. The mirror structure is helpful to enhance light absorption for a solar cell with a thin absorption layer. After the thin-film process for a conventional sapphire-based p-i-n solar cell, the device exhibits an enhancement factor of 57.6% in current density and an increment in conversion efficiency from 0.55% to 0.80%. The physical origin for the photocurrent enhancement in the thin-film solar cell is related to multireflection of light by the mirror structure.

Keywords

III-V semiconductors; current density; gallium compounds; indium compounds; laser materials processing; photoconductivity; semiconductor thin films; solar cells; thin film devices; wafer bonding; GaN-InGaN; conversion efficiency; current density; enhancement factor; laser lift-off technique; light absorption; light multireflection; mirror-coated substrate; p-i-n structure; photocurrent enhancement; photovoltaic characteristics; thin absorption layer; thin-film solar cells; wafer bonding; Laser lift-off; thin-film solar cell; wafer bonding;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2009.2021414

Filename

5061603