Download or read book Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination written by Richard Dillon Kramer and published by . This book was released on 1994 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, preliminary results of a new approach for annealing previously irradiated Gallium Arsenide solar cells is reported. This technique examines the use of laser illumination to induce Forward-Biased current annealing. Five GaAs solar cells were irradiated with 65 MeV electrons at varying fluence levels. Visible laser light produced a 0.5 A/sq cm forward-biased current density and raised the solar cell temperature by 30 deg C. Ten to fifteen percent recovery of degraded parameters was achieved in four of the five tested cells. The results show that a laser can produce some annealing in radiation damaged GaAs solar cells. Further investigation into the results also indicate that the 65 MeV energy level of the electron irradiation could have caused unrecoverable permanent damage to the solar cells. Follow up research of this annealing technique should be conducted on GaAs cells that are being irradiated at a lower energy level as well as lower fluence level. Repetitive annealing of lightly damaged cells in previous research has provided appreciative recovery using forward bias current techniques. One can expect similar results using the laser induced annealing technique proposed in this research.
Download or read book Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination written by Richard Dillon Kramer and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, preliminary results of a new approach for annealing previously irradiated Gallium Arsenide solar cells is reported. This technique examines the use of laser illumination to induce Forward-Biased current annealing. Five GaAs solar cells were irradiated with 65 MeV electrons at varying fluence levels. Visible laser light produced a 0.5 A/sq cm forward-biased current density and raised the solar cell temperature by 30 deg C. Ten to fifteen percent recovery of degraded parameters was achieved in four of the five tested cells. The results show that a laser can produce some annealing in radiation damaged GaAs solar cells. Further investigation into the results also indicate that the 65 MeV energy level of the electron irradiation could have caused unrecoverable permanent damage to the solar cells. Follow up research of this annealing technique should be conducted on GaAs cells that are being irradiated at a lower energy level as well as lower fluence level. Repetitive annealing of lightly damaged cells in previous research has provided appreciative recovery using forward bias current techniques. One can expect similar results using the laser induced annealing technique proposed in this research.
Download or read book Annealing of Radiation damaged Indium Phosphide and Gallium Arsenide Solar Cells Through Laser Illumination written by Charles T. Chase and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annealing of Defect Sites in Radiation Damaged Indium Phosphide Solar Cells Through Laser Illumination written by Charles T. Chase and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the results of a laser annealing technique used to remove defect sites from radiation damaged indium phosphide diffused junction solar cells. This involves the illumination of damaged solar cells with a continuous wave laser to produce a moderate heating and a large forward-biased current. The InP cells were irradiated with 27 MeV electrons to a given fluence, and tested for degradation. Light from an argon laser was used to illuminate each cell with an irradiance of 2.5 W/sq cm, producing a current density 7 to 10 times larger than under AMO conditions. Cells were annealed at 48.5 deg C, 60 deg C, and 75 deg C for periods of 15 to 60 minutes, and cooled to 25 deg C for power recovery determination. Annealing at 48.5 deg C resulted in a recovery of 17 to 18% of the power lost due to irradiation, and annealing cells at 60 deg C produced a recovery of 43 to 48%. A single test of the technique at 75 deg C produced a net recovery of only 21% of the power lost. These results indicate that significant power recovery results from the annealing of defects within InP solar cells. Continuing research should involve the repeating of the test at 75 deg C, and irradiations with electrons or protons of energies expected in the space environment.
Download or read book Annealing of Defect Sites in Radiation Damaged Indium Phosphide Solar Cells Through Laser Illumination written by Charles T. Chase and published by . This book was released on 1995 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the results of a laser annealing technique used to remove defect sites from radiation damaged indium phosphide diffused junction solar cells. This involves the illumination of damaged solar cells with a continuous wave laser to produce a moderate heating and a large forward-biased current. The InP cells were irradiated with 27 MeV electrons to a given fluence, and tested for degradation. Light from an argon laser was used to illuminate each cell with an irradiance of 2.5 W/sq cm, producing a current density 7 to 10 times larger than under AMO conditions. Cells were annealed at 48.5 deg C, 60 deg C, and 75 deg C for periods of 15 to 60 minutes, and cooled to 25 deg C for power recovery determination. Annealing at 48.5 deg C resulted in a recovery of 17 to 18% of the power lost due to irradiation, and annealing cells at 60 deg C produced a recovery of 43 to 48%. A single test of the technique at 75 deg C produced a net recovery of only 21% of the power lost. These results indicate that significant power recovery results from the annealing of defects within InP solar cells. Continuing research should involve the repeating of the test at 75 deg C, and irradiations with electrons or protons of energies expected in the space environment.
Download or read book Forward Biased Current Annealing of Radiation Damaged Gallium Arsenide and Silicon Solar Cells written by Richard L. Staats and published by . This book was released on 1987 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation damaged gallium arsenide and silicon solar cells were annealed using a combination of thermal and Forward-bias Current Annealing techniques. These cells were annealed under varying current densities from 0.125 A/sq. cm 2 to 1.250 A/sq. cm. 2 and at temperatures from 90 C to 140 C. Gallium arsenide solar cells annealed at current densities from 0.250 A/sq. cm. 2 to 0.750 A/sq. cm. 2. Attempts to anneal silicon solar cells failed to produce positive results at all current densities. The primary application of this research is to determine the feasibility of on-orbit annealing of a satellite's solar array. At present, only silicon solar cells are deployed in space to provide electric power for satellites. When GaAs solar cells become space qualified, on-orbit Forward-bias Current Annealing of these solar arrays may significantly increase the end of life of orbiting satellites. Keywords: Gallium arsenide, Silicon; Solar cells; Annealing.
Download or read book Analysis of Radiation Damaged and Annealed Gallium Arsenide and Indium Phosphide Solar Cells Using Deep Level Transient Spectroscopy written by Joseph A. Bruening and published by . This book was released on 1993 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power loss in spacecraft solar cells due to radiation damage was investigated. The mechanisms behind the degradation and based on deep-level defects in the crystalline lattice structure of the solar cell. Through a process known as Deep Transient Spectroscopy (DLTS), a correlation can be made between damage/recovery and trap energy of the cell. Gallium (GaAs/Ge) and Indium Phosphide (InP) solar cells were subjected to 1 MeV electron irradiation, to fluences of 1E16 electrons/sq cm. Attempts at recovery included thermal annealing, alone, and with an applied forward bias current, and injection annealing. Various cycles of irradiation, annealing and DLTS were performed, in an attempt to correlate damage to trap energy level and growth. The results show that DLTS cannot be performed on GaAs/Ge, and no recovery was apparent in these cells. DLTS analysis of InP indicated excellent photoinjection annealing recovery at a variety of temperatures. Lower energy level defects are associated with the recovery of the cells while the higher energy traps are indicative of permanent degradation in the Inp solar cells. Applying this information to future research could increase satellite mission life, and significantly reduce space mission costs. Radiation damage in solar cells, DLTS, Annealing, Heterojunction, Gallium arsenide, Indium phosphide.
Download or read book Forward bias Current Annealing of Radiation Damaged Gallium Arsenide and Silicon Solar Cells written by Richard L. Staats and published by . This book was released on 1987 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Power Recovery of Radiation Damaged MOCVD Grown Indium Phosphide on Silicon Solar Cells Through Argon ion Laser Annealing written by Lynn L. Boyer and published by . This book was released on 1996 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the results of a laser annealing technique used to remove defect sites from radiation damaged indium phosphide on silicon MOCVD grown solar cells. This involves the illumination of damaged solar cells with a continuous wave laser to produce a large forward-biased current. The InP/Si cells were irradiated with 1 MeV electrons to a given fluence, and tested for degradation. Light from an argon laser was used to illuminate four cells with an irradiance of 2.5 W/sq cm, producing a current density 3 to 5 times larger than AMO conditions. Cells were annealed at 19 deg C with the laser and at 25 deg C under AMO conditions. Annealing under laser illumination of n/p-type cells resulted in recovery of 48%. P/n type cells lost 4 to 12% of the assumed degradaton. Annealing under AMO conditions resulted in power recovery of 70% in n/p type cells. P/n-type cells recovered approximately 16% of lost power. Results indicate that significant power recovery results from the annealing of defects within n/p type InP/Si solar cells. Distribution Limitation(s).
Download or read book Analysis of Radiation Damaged and Annealed Gallium Arsenide and Indium Phosphide Solar Cells Using Deep Level Transient Spectroscopy written by and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power loss in spacecraft solar cells due to radiation damage was investigated. The mechanisms behind the degradation and based on deep-level defects in the crystalline lattice structure of the solar cell. Through a process known as Deep Transient Spectroscopy (DLTS), a correlation can be made between damage/recovery and trap energy of the cell. Gallium (GaAs/Ge) and Indium Phosphide (InP) solar cells were subjected to 1 MeV electron irradiation, to fluences of 1E16 electrons/sq cm. Attempts at recovery included thermal annealing, alone, and with an applied forward bias current, and injection annealing. Various cycles of irradiation, annealing and DLTS were performed, in an attempt to correlate damage to trap energy level and growth. The results show that DLTS cannot be performed on GaAs/Ge, and no recovery was apparent in these cells. DLTS analysis of InP indicated excellent photoinjection annealing recovery at a variety of temperatures. Lower energy level defects are associated with the recovery of the cells while the higher energy traps are indicative of permanent degradation in the Inp solar cells. Applying this information to future research could increase satellite mission life, and significantly reduce space mission costs. Radiation damage in solar cells, DLTS, Annealing, Heterojunction, Gallium arsenide, Indium phosphide.
Download or read book Power Recovery of Radiation Damaged MOCVD Grown Indium Phosphide on Silicon Solar Cells Through Argon Ion Laser Annealing written by Lynn L. Boyer and published by . This book was released on 1996-06-01 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the results of a laser annealing technique used to remove defect sites from radiation damaged indium phosphide on silicon MOCVD grown solar cells. This involves the illumination of damaged solar cells with a continuous wave laser to produce a large forward-biased current. The InP/Si cells were irradiated with 1 MeV electrons to a given fluence, and tested for degradation. Light from an argon laser was used to illuminate four cells with an irradiance of 2.5 W/sq cm, producing a current density 3 to 5 times larger than AMO conditions. Cells were annealed at 19 deg C with the laser and at 25 deg C under AMO conditions. Annealing under laser illumination of n/p-type cells resulted in recovery of 48%. P/n type cells lost 4 to 12% of the assumed degradaton. Annealing under AMO conditions resulted in power recovery of 70% in n/p type cells. P/n-type cells recovered approximately 16% of lost power. Results indicate that significant power recovery results from the annealing of defects within n/p type InP/Si solar cells.
Download or read book Analysis of Radiation Damaged and Annealed Gallium Arsenide and Indium Phosphide Solar Cells Using Deep Level Transient Spectroscopy Techniques written by and published by . This book was released on 1991 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Degradation of solar cell performance from radiation damage was found to be reversed through annealing processes. The mechanisms behind the degradation and recovery is based on deep-level traps, or defects, in the lattice structure of the solar cell. Through a process known as Deep Level Transient Spectroscopy (DLTS), a correlation can be made between damage/recovery and trap energy level/concentration of the cell. Gallium Arsenide (GaAs) and Indium Phosphide (InP) solar cells were subjected to 1 MeV electron irradiation by a Dynamitron linear acceleration at two fluence levels of 1E14 and 1E15 electrons/sq cm. The process of annealing included thermal annealing at 90 C with forward bias current and thermal annealing alone (for GaAs). After each cycle, DLTS measurements were taken to determine the energy level of the traps and their concentration. Multiple cycles of irradiation, annealing and DLTS were performed to observe the correlation between degradation and recovery to trap energy level and concentration. The results show that the lower energy level traps are associated with the recovery of the cells while the higher level traps are associated with the overall permanent degradation of the cells.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Test of Minority Carrier Annealing on Gallium Arsenide Solar Cells Using Forward Biased Current written by Thomas F. Clark and published by . This book was released on 1986 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been recent interest in providing an on-orbit solar cell annealing capability. Minority carrier injection annealing was examined using a 0.5A/cm2 forward-biased current density on gallium arsenide solar cells in a 90 degree centigrade ambient environment. The cells had been irradiated with 1-Mev electrons for a total fluence of 3El5el/cm2. When annealing stopped, after 48 hours, the procedure had recovered 30% of the maximum power that was lost due to radiation damage. This procedure may have on-orbit potential. Keywords include: Gallium Arsenide; Solar Cells; and Annealing.
Download or read book Solar Energy Update written by and published by . This book was released on 1984 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy a Continuing Bibliography with Indexes written by and published by . This book was released on 1980 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
