Engineering Papers⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 3412152

Identifying Suitable Front Contacts for High‐Efficiency Cd(Se,Te) Solar Cells on Space‐Qualified Cover Glass

Patel, Aesha P. [University of Toledo, OH (United States); National Laboratory of the Rockies (NLR), Golden, CO (United States)]·Muzzio, Ryan [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000246699633)·Young, Matthew R. [National Laboratory of the Rockies (NLR), Golden, CO (United States)]·Morrissey, Robert [National Laboratory of the Rockies (NLR), Golden, CO (United States)]·Chaulagain, Suresh [University of Toledo, OH (United States)]·Sartor, B. Edward [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000166618645)·Kaluarachchi, Prabodika N. [University of Toledo, OH (United States)]·Velez, Christian [National Laboratory of the Rockies (NLR), Golden, CO (United States)]·Brown, Joshua A. [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000245429033)·Shrestha, Bishal [University of Toledo, OH (United States)]·Duenow, Joel N. [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000284574022)·Glynn, Stephen [National Laboratory of the Rockies (NLR), Golden, CO (United States)]·Heben, Michael J. [University of Toledo, OH (United States)]·Song, Zhaoning [University of Toledo, OH (United States)] (ORCID:0000000266770994)·Podraza, Nikolas J. [University of Toledo, OH (United States)]·Phillips, Adam B. [University of Toledo, OH (United States)] (ORCID:0000000226755052)·Ellingson, Randy J. [University of Toledo, OH (United States)] (ORCID:0000000195206586)·Reese, Matthew O. [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000199275984)
View original source ↗Read source document ↗Export metadata ↓

Abstract

Deployment of photovoltaics in space requires devices that combine high-efficiency, low areal mass, and resilience to harsh environments. Historically, high-efficiency multijunction III–V materials have dominated space power systems; however, their high cost and limited manufacturing throughput motivate the exploration of scalable alternatives. While CdTe-based thin-film photovoltaics offer an attractive option, their performance on non-conventional substrates can suffer from front contact instability under higher-temperature processing. Here, the role of front contact chemistry in limiting cell performance is investigated using CdTe-based devices fabricated on 150 μm thick Ceria-doped space-qualified 0214 Corning glass. A matrix of four transparent conducting oxides (TCOs: CTO, AZO, ITO, IZO) combined with two n-type emitters (MZO, IGO) reveals chemical stability at the front interface—rather than absorber composition alone—governs recombination losses, voltage deficits, and device reproducibility. Chemically stable front contact combinations suppress elemental diffusion and interfacial degradation, resulting in significantly improved carrier lifetimes and junction quality. These insights are validated through record-certified Cd(Se,Te) cell efficiencies of 18.4% under AM1.5G and 16.2% under AM0 illumination on ultra-thin glass. Beyond CdTe, this work provides a general framework for the rational selection of TCO/emitter interfaces in superstrate thin-film photovoltaics, including emerging technologies like metal halide perovskites, while enabling high-efficiency, lightweight photovoltaics for space applications.

Explore related subjects

14 SOLAR ENERGYCdTe solar cellsCdTe-based (Cd(Se,Te))emitterfront contactfront interfacesolar cellsspace photovoltaicsspace qualifiedthin filmstransparent conducting oxide (TCO)

Keep this discovery

BibTeXRIS

Patel, Aesha P. [University of Toledo, OH (United States); National Laboratory of the Rockies (NLR), Golden, CO (United States)], Muzzio, Ryan [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000246699633), Young, Matthew R. [National Laboratory of the Rockies (NLR), Golden, CO (United States)], Morrissey, Robert [National Laboratory of the Rockies (NLR), Golden, CO (United States)], Chaulagain, Suresh [University of Toledo, OH (United States)], Sartor, B. Edward [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000166618645), Kaluarachchi, Prabodika N. [University of Toledo, OH (United States)], Velez, Christian [National Laboratory of the Rockies (NLR), Golden, CO (United States)], Brown, Joshua A. [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000245429033), Shrestha, Bishal [University of Toledo, OH (United States)], Duenow, Joel N. [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000284574022), Glynn, Stephen [National Laboratory of the Rockies (NLR), Golden, CO (United States)], Heben, Michael J. [University of Toledo, OH (United States)], Song, Zhaoning [University of Toledo, OH (United States)] (ORCID:0000000266770994), Podraza, Nikolas J. [University of Toledo, OH (United States)], Phillips, Adam B. [University of Toledo, OH (United States)] (ORCID:0000000226755052), Ellingson, Randy J. [University of Toledo, OH (United States)] (ORCID:0000000195206586), Reese, Matthew O. [National Laboratory of the Rockies (NLR), Golden, CO (United States)] (ORCID:0000000199275984). 2026-06-30. Identifying Suitable Front Contacts for High‐Efficiency Cd(Se,Te) Solar Cells on Space‐Qualified Cover Glass. https://doi.org/10.1002/pip.70128

Cite the original work for its findings. Save a collection to share your selection of sources.

Discover connections

14 SOLAR ENERGY subjectThin films subject

Connections use source metadata and explicit phrase matches, not verified experimental comparisons.

KEEP EXPLORING

Related reports

DOE OSTI2026

Low-Temperature Gold Deposition Improves CdTe Back Contacts

Improved back contacts can benefit CdTe photovoltaics (PV). In this work, Cd(Se,Te) PV absorbers are cooled during Au evaporation to thermally quench a chemical reaction occurring between gold and CdTe and the generation of a reaction product that lowers device efficiency. Reducing substrate temperature enhances PV power conversion efficiency via open-circuit voltage and fill factor increases. X-ray photoelectron spectroscopy (XPS) reveals that lower temperature also reduces chemical perturbations of the CdTe, potentially linking back contact formation to a CdTe degradation product that hinders PV performance. Comparing reaction enthalpy and substrate heating energy shows that back contact formation by sputtering elemental metals onto ZnTe may exhibit a degradation pathway analogous to that of CdTe/Au reported here. Degradation-diminishing contact formation processes are therefore of general interest for optoelectronic devices, and the reduced substrate temperature in this study is one example.

14 SOLAR ENERGY↗
DOE OSTI2026

Impact of the Annealing Temperature on the Local Se Distribution and Optical Properties in CdSexTe1-x Solar Cells by Multimodal X-ray Microscopy

The introduction of Se in CdTe solar-cell absorbers has led to multiple beneficial effects in the devices, including an increased short-circuit current and an extended charge-carrier lifetime. A critical manufacturing step of CdSexTe1-x solar cells is CdCl2 annealing at high temperatures, during which Se diffuses through the absorber layer. Understanding the local Se distribution in the absorber and its impact on optical properties of the material is key for the further development of this thin-film solar cell technology. In a multimodal x-ray scanning microscopy approach, we investigated the impact of the annealing temperature of CdSexTe1-x solar cells on the Se distribution and on optical characteristics of the material. For this purpose, we exploited an upgraded x-ray excited optical luminescence (XEOL) detection unit that enables simultaneous spectrally and temporally resolved XEOL mapping at synchrotron facilities that are ideal for studying thin-film solar-cell materials with hard x-rays featuring high penetration depth and lateral resolution.

14 SOLAR ENERGY↗
NASA NTRS1994

Vapor Transport Crystal Growth of Mercury-Cadmium-Telluride in Microgravity

Two epitaxial growth experiments of Hg 1-x Cd x Te layers on (100) CdTe substrates in closed ampoules using HgI 2 as a transport agent have been performed during the USML-1 mission. The characterization results to date demonstrate a considerable improvement of the space-grown epitaxial layers relative to ground-control specimens in terms of morphology, compositional uniformity, and structural micro homogeneity. These results show the effects of microgravity and fluid dynamic disturbances on-ground on the deposition and growth processes. The continued analysis of this technologically important system is designed to further elucidate the observed crystallographic improvements and their relation to mass flow.

Heribert Wiedemeier↗