Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 2574709

Solar Cell Performance after Exfoliation Using Sonic Liftoff

Neumann, Anica N. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Colorado School of Mines, Golden, CO (United States)] (ORCID:0000000290944157)·Coll, Pablo G. [Crytal Sonic Inc., Phoenix, AZ (United States)]·Sindermann, Andrew B. [Rochester Inst. of Technology, Rochester, NY (United States)]·Polly, Stephen J. [Rochester Inst. of Technology, Rochester, NY (United States)]·Hubbard, Seth M. [Rochester Inst. of Technology, Rochester, NY (United States)]·Bathurst, Lara J. [Crytal Sonic Inc., Phoenix, AZ (United States)]·Warren, Emily L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)]·Steiner, Myles A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)]·Bertoni, Mariana I. [Crytal Sonic Inc., Phoenix, AZ (United States); Arizona State Univ., Tempe, AZ (United States)] (ORCID:000000020415837X)
View original source ↗Read source document ↗Export metadata ↓

Abstract

Removing grown device layers from a GaAs substrate is an essential aspect of reducing costs of III–V photovoltaics. While many methods of device layer removal have been explored, Sonic Lift‐off (SLO) demonstrates novel control of the stress conditions within the substrate during exfoliation. By utilizing acoustic energy, this technique allows for a lower maximum stress required to fully lift‐off layers from a substrate. We demonstrate that this technique results in no damage to inverted‐grown and upright‐grown exfoliated devices. The inverted device demonstrated an efficiency of 26.8% after SLO in comparison to 26.5% for a traditionally‐processed cell, and the upright device showed a 22.0% efficiency after SLO. The SLO process has been shown to produce exfoliated, damage‐free devices and opens the door for substrate reuse to reduce the cost of III–V photovoltaics.

Explore related subjects

14 SOLAR ENERGYIII-Vphotovoltaicspalling

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Neumann, Anica N. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Colorado School of Mines, Golden, CO (United States)] (ORCID:0000000290944157), Coll, Pablo G. [Crytal Sonic Inc., Phoenix, AZ (United States)], Sindermann, Andrew B. [Rochester Inst. of Technology, Rochester, NY (United States)], Polly, Stephen J. [Rochester Inst. of Technology, Rochester, NY (United States)], Hubbard, Seth M. [Rochester Inst. of Technology, Rochester, NY (United States)], Bathurst, Lara J. [Crytal Sonic Inc., Phoenix, AZ (United States)], Warren, Emily L. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)], Steiner, Myles A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)], Bertoni, Mariana I. [Crytal Sonic Inc., Phoenix, AZ (United States); Arizona State Univ., Tempe, AZ (United States)] (ORCID:000000020415837X). 2025-06-24. Solar Cell Performance after Exfoliation Using Sonic Liftoff. https://doi.org/10.1002/solr.202500049

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

KEEP EXPLORING

Related reports

DOE OSTI2026

Heliostat sizing methodology for concentrating solar thermal industrial process heat projects

This study presents a method to obtain a heliostat size that minimizes the levelized cost of heat (LCOH) of a heliostat-based concentrating solar thermal system for applications of solar heating for industrial processes at operating temperatures from 565 to 1550°C. The method extends prior work by embedding a routine for system design that obtains near-optimal subsystem sizes, increasing the fidelity of drive cost functions, and adding an optical performance model to supplement the previously developed cost models, which we update to reflect current pricing trends. An illustrative business case is developed for Daggett, California, targeting specified annual thermal energy outputs of 50 to 400 GWh th . Optical performance is modeled using verified estimates from the literature. A surrogate heliostat cost model, derived from commercial heliostat designs and scaled for production volume, installation, and operations and maintenance costs, is used to develop cost functions. Results show that heliostat size strongly affects the LCOH, producing a characteristic U-shaped trend with a robust near-optimal window of 7-20 m 2 ; the heliostat size producing the lowest project cost in our study grows slightly as the project size increases, and is reduced as the operating temperature increases. The findings in this study are consistent with the general trend of smaller heliostats being deployed at existing projects for high-temperature industrial process heat and reflect the significant reduction in power electronics and other per-heliostat costs. The methodology we propose is general and can be tailored to revised cost curves as the technology continues to evolve.

14 SOLAR ENERGY↗
DOE OSTI2026

A Sensitivity-driven Wide Area Protection (SWAP) Coordination Tool for High Penetration of Inverter-based Resources (IBR)

Traditionally, power system generation sources have been composed of synchronous generators, of which the fault current behavior is understood with minimal differences between generation size and types due to the physics of their construction. Present protection schemes and modeling methods are based upon these understood characteristics. Most renewable generation is composed of inverter-based resources (IBR), in which fault current is determined by switching control software and hardware limitations, each of which can vary between manufacturers and even between models of the same manufacturer. The resulting fault current is low in magnitude, low in negative-sequence current, unpredictable phase angles, and is a challenge to model. These characteristics also result in a challenge to traditional protection schemes and fault simulation software. To address several of these concerns, the project has the following goals: 1. Improve IBR models: Improve IBR models used in short circuit (SC) programs to accurately capture the response of IBRs at the bulk power system (BPS) level for fault and protection studies. 2. Develop automation tool: Develop an automation tool that allows engineers to identify protection coordination and sensitivity issues by performing SC and protection coordination studies in a high IBR-penetrated grid by applying variations to the IBR models, faults, contingencies, etc. 3. Develop schemes: Develop new protection mitigation solution schemes that complement the existing protection systems to ensure safe operation of the BPS with higher IBR penetration levels. The project team did not achieve this final goal, as the Department of Energy (DOE) stopped the project early due to changes in DOE funding priorities. The termination notice came at the beginning of the final project phase, while the team was identifying and beginning to investigate protection issues. It should be noted that the team discussed a 100% penetration scenario. However, this scenario would require the use of grid-forming IBR models that are not presently available. Since developing these models requires additional effort, the 100% penetration scenario was not pursued during this project. In the future, developing the methodology and models for the 100% scenario could benefit the industry.

14 SOLAR ENERGY↗
DOE OSTI2026

Technoeconomic Analysis Round Robin of a Retrofit of the Ivanpah Concentrating Solar Plant with a Molten-Salt System with Thermal Energy Storage

While the fidelity of technoeconomic analysis (TEA) models for concentrating solar thermal systems has improved in recent years, there is a lack of consensus on the specific inputs used to forecast performance of a newly built tower system due to a lack of validations and post-mortems available to the public. This effort is a joint initiative between multiple international organizations to validate and compare their TEA models. The specific case study is a proposed retrofit of one unit of the Ivanpah Solar Energy Generating System to include molten-salt storage, replacing the steam generation system with a molten-salt receiver, salt-to-steam heat exchanger train, and new balance of plant while keeping the existing steam turbine, solar field, and interconnection in place, using plant data for calibration. This manuscript discusses several of the agreed-upon assumptions for this study as well as a preliminary analysis from prior work that motivates the study.

14 SOLAR ENERGY↗