Super radiation tolerance of CIGS solar cells demonstrated in space by MDS-1 satellite
ABSTRACT High radiation tolerance of CIGS solar cells is demonstrated in space for the first time by monitoring the performance of Cu(In,Ga)Se/sub 2/ thin-film solar cells on MDS-1 since February 2002. Short-circuit current of the CIGS cells did not degrade and open-circuit voltage of the cells degraded only about 1%. In contrast, the performance of other solar cells on the satellite, including Si and GaAs space solar cells, degraded 1 year after launch. The high recovery of radiation damage of ClGS solar cells due to thermal annealing was found from ground test. We predicted the degradation of the CIGS solar cells in space using the relative degradation coefficient, the annealing rates of Voc and Isc for protons irradiating the cells and the radiation response of the cells without thermal annealing. The results are in good agreement with flight data of the CIGS solar cells on the satellite. We were thus able to demonstrate high radiation tolerance of CIGS solar cells in space for the first time.
Conference Proceeding: Air Force Perspective on Present and Future Space Power Generation[show abstract] [hide abstract]
ABSTRACT: Photovoltaics continue to be the primary source for electric power for space missions. The need for ever higher power, specific power, areal power density, and radiation resistance continues to push development of novel solar cell technologies. To meet present and future space power requirements, conventional crystalline multijunction solar cells, next generation thin-film solar cells, and novel technologies are being pursued. In the near to mid term, III-V based multijunction solar cell efficiencies are being increased through incorporation of new materials and metamorphic structures. These efforts are expected to result in AM0 solar cell efficiencies of 33-35%. For thin-film solar cells, significant progress has been made in moving to lightweight polymer substrates and incorporation of monolithic integration, pushing cell level specific powers over 1800 W/kg. Efficiencies continue to increase through better process control and post process treatments. Incorporation of new materials and tandem structures promises to further increase thin-film solar cell efficiencies. For the longer term, novel material systems and nanotechnologies are being investigated. Examples are InGaN alloys which show promise for a continuously varied bandgap with composition, and intermediate bandgap or nanostructured solar cells which take advantage of size dependant light absorption to absorb more of the solar spectrum. To take advantage of new technologies, novel module and array structures are also being developedPhotovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on; 06/2006
Conference Proceeding: Opportunities in photovoltaics for space power generation[show abstract] [hide abstract]
ABSTRACT: Photovoltaics provide virtually all power generation for space systems, and the majority of these, in recent years, are multijunction solar cells comprised of III-V materials. Multijunction solar cells are designed for optimal efficiency under the space AM0 (Air Mass Zero) solar spectrum and to operate with high reliability under hostile environmental conditions. State of practice crystalline multijunction solar cells are primarily triple junction (GaInP<sub>2</sub>/GaAs/Ge) grown on Ge single crystal wafers. Development efforts are focused on increasing the efficiency of these cells beyond 30%. For next-generation spacecraft, space compatible thin-film solar cells are being developed. Nanotechnology and novel materials hold promise for extending cell performance beyond these technologies. Opportunities for space-qualified solar cells extend from commercial and government satellites, where power demands continue to grow, to power generation systems on the high altitude airships being developed in several nations.Photovoltaic Specialists Conference, 2005. Conference Record of the Thirty-first IEEE; 02/2005