SBIR-STTR Award

This phase I project will develop and merge the different technologies to reduce the defect-density of mid-bandgap (1.4 eV) chalcopyrite based solar absorbers to enable > 15% efficient modules (at standard test conditions) on lightweight and flexible polymer substrates. As an added benefit, the mid-bandgap device will improve the performance of CIGS-based devices for space applications by enable 30% higher performance at nominal operational temperatures due to lower temperature coefficients and reduced joule-heating losses. The defect-density reducing technologies that will be developed are listed as follows: 1) Higher-temperature capable PBO polymer substrates enabling higher processing temperatures (> 600ºC), 2) Higher conductivity and stress reducing back contact structures enabling lower stress solar absorbers and 3) Ag alloying in mid-bandgap CIGS solar absorbers. Each of these approaches have been demonstrated to reduce defects and will be merged for the first time under this proposed project while leveraging earlier development with the individual components.

Benefit:
We have a natural evolution of our product development through R&D, Roll-to-roll Prototype, 1.5MW Production, 25MW production, and beyond. Commercialization of the mid-bandgap devices will be marked by demonstration on the 1.5MW facility, but materials for evaluation will be available much sooner, namely when demonstrated on the prototype line. Mid-bandgap modules with High-T substrates will likely represent the second or third generation of product from AST, the first being baseline single-junction CIGS. Our customers for this product will be defense agencies/contractors (space and satellite power, near space reconnaissance, battle field power solutions packs, solar powered tents, portable power), power electronics OEMs, building material solution providers, and PV system integrators for both the commercial and residential building product markets. Our lightweight, high specific power product can be incorporated into fabric, structural composites, and polymeric circuitry to present advantages over ultra-high efficiency expensive multijunction PV. We will be able to demonstrate this technology on the 1.5MW line and gain experience with the higher-performance products. Phase II work of this project will feed directly into pre-production demonstration and process validation. Given a nominal one to two-year gestation of the product, we can expect a device achieving true commercialization sometime after 2012.

Keywords:
Mid-Bandgap Cigs, High Temperature Substrate, Polymer, Chalcopyrite, Silver Copper Indium Gallium Diselenide, Polyphenylene Benzobisoxazole, Thin Film Photovoltaic, Flexible

Phase II will leverage the success of Phase I, as well as integrate advances from internal programs, to scale up development of mid-bandgap (1.4 eV) chalcopyrite-based PV. We will optimize chemistries of the device, as well as enable increased temperature for reduced the defect density by a combination of new substrates and refined thermal management to enable > 15% efficient modules on lightweight and flexible polymer substrates. As an added benefit, mid-bandgap devices will improve the performance of CIGS-based devices for space applications by enable 30% higher performance at nominal operational temperatures due to lower temperature coefficients and reduced joule-heating losses. We will address the following: 1) optimize the thermal management of the process to enable better coupling of thermal energy to the back contact and utilize high-temperature substrates with reduced coefficient of thermal expansion (CTE), 2) optimize the back contact of the device to best match electrical and mechanical requirements of this improved process, 3) optimize flexible mid-bandgap AgCIGS and buffer layers in order to achieve desired electrical and mechanical performance, and 4) optimize submodule design, patterning and printing for the new mid-bandgap material. Each of these approaches have been demonstrated to reduce defects.

Benefit:
We have a natural evolution of our product development through R&D, Roll-to-roll Prototype/Development (within R&/ Engineering) and Production. Commercialization of the mid-bandgap devices will be marked by demonstration on R&D?s decommissioned production equipment. Mid-bandgap modules with High-Temperature substrates will likely represent the second or third generation of product from AST, the first being our production single-junction flexible monolithically integrated CIGS product. Our customers for this product will be defense agencies/contractors (space and satellite power, near space reconnaissance, battle field power solutions packs, solar powered tents, portable power), power electronics OEMs and consumer electronic products, building material solution providers, and PV system integrators for both the commercial and residential building product markets. Our lightweight, high specific power product can be incorporated into fabric, structural composites, and polymeric circuitry to present advantages over ultra-high efficiency expensive multijunction PV. In Phase II, we specifically will be able to evaluate production readiness of the thin film device, patterning and printing operations at AST, as well as supply chain readiness.

Keywords:
Mid-Bandgap Cigs, High Temperature Substrate, Polymer, Chalcopyrite, Silver Copper Indium Gallium Diselenide, Thin Film Photovoltaic, Flexible