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Title: A study of contacts and back-surface reflectors for 0.6-eV Ga{sub 0.32}In{sub 0.68}As/InAs{sub 0.32}P{sub 0.68} thermophotovoltaic monolithically interconnected modules

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.57836· OSTI ID:354502
; ; ; ; ;  [1]
  1. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

Thermophotovoltaic (TPV) systems have recently rekindled a high level of interest for a number of applications. In order to meet the requirement of low-temperature ({approximately}1000&hthinsp;{degree}C) TPV systems, 0.6-eV Ga{sub 0.32}In{sub 0.68}As/InAs{sub 0.32}P{sub 0.68} TPV monolithically interconnected modules (MIMs) have been developed at the National Renewable energy Laboratory (NREL) [1]. The successful fabrication of Ga{sub 0.32}In{sub 0.68}As/InAs{sub 0.32}P{sub 0.68} MIMs depends on developing and optimizing of several key processes. Some results regarding the chemical vapor deposition (CVD)-SiO{sub 2} insulating layer, selective chemical etch via sidewall profiles, double-layer antireflection coatings, and metallization via interconnects have previously been given elsewhere [2]. In this paper, we report on the study of contacts and back-surface reflectors. In the first part of this paper, Ti/Pd/Ag and Cr/Pd/Ag contact to n-InAs{sub 0.32}P{sub 0.68} and p-Ga{sub 0.32}In{sub 0.68}As are investigated. The transfer length method (TLM) was used for measuring of specific contact resistance R{sub c}. The dependence of R{sub c} on different doping levels and different pre-treatment of the two semiconductors will be reported. Also, the adhesion and the thermal stability of Ti/Pd/Ag and Cr/Pd/Ag contacts to n-InAs{sub 0.32}P{sub 0.68} and p-Ga{sub 0.32}In{sub 0.68}As will be presented. In the second part of this paper, we discuss an optimum back-surface reflector (BSR) that has been developed for 0.6-eV Ga{sub 0.32}In{sub 0.68}As/InAs{sub 0.32}P{sub 0.68} TPV MIM devices. The optimum BSR consists of three layers: {approximately}1300 {Angstrom} MgF{sub 2} (or {approximately}1300 {Angstrom} CVD SiO{sub 2}) dielectric layer, {approximately}25 {Angstrom} Ti adhesion layer, and {approximately}1500 {Angstrom} Au reflection layer. This optimum BSR has high reflectance, good adhesion, and excellent thermal stability. {copyright} {ital 1999 American Institute of Physics.}

Sponsoring Organization:
USDOE
OSTI ID:
354502
Report Number(s):
CONF-981055-; ISSN 0094-243X; TRN: 9913M0017
Journal Information:
AIP Conference Proceedings, Vol. 460, Issue 1; Conference: 4. National Renewable Energy Laboratory (NREL) conference on thermophotovoltaic generation of electricity, Denver, CO (United States), 11-14 Oct 1998; Other Information: PBD: Mar 1999
Country of Publication:
United States
Language:
English