Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination

Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination PDF Author: Richard Dillon Kramer
Publisher:
ISBN:
Category :
Languages : en
Pages : 84

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Book Description
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.

Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination

Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination PDF Author: Richard Dillon Kramer
Publisher:
ISBN:
Category :
Languages : en
Pages : 84

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Book Description
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.

Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination

Annealing of Radiation Damaged Gallium Arsenide Solar Cells by Laser Illumination PDF Author: Richard Dillon Kramer
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
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.

Annealing of Radiation-damaged Indium Phosphide and Gallium Arsenide Solar Cells Through Laser Illumination

Annealing of Radiation-damaged Indium Phosphide and Gallium Arsenide Solar Cells Through Laser Illumination PDF Author: Charles T. Chase
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Annealing of Defect Sites in Radiation Damaged Indium Phosphide Solar Cells Through Laser Illumination

Annealing of Defect Sites in Radiation Damaged Indium Phosphide Solar Cells Through Laser Illumination PDF Author: Charles T. Chase
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
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.

Annealing of Defect Sites in Radiation Damaged Indium Phosphide Solar Cells Through Laser Illumination

Annealing of Defect Sites in Radiation Damaged Indium Phosphide Solar Cells Through Laser Illumination PDF Author: Charles T. Chase
Publisher:
ISBN:
Category :
Languages : en
Pages : 113

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Book Description
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.

Forward-Biased Current Annealing of Radiation Damaged Gallium Arsenide and Silicon Solar Cells

Forward-Biased Current Annealing of Radiation Damaged Gallium Arsenide and Silicon Solar Cells PDF Author: Richard L. Staats
Publisher:
ISBN:
Category :
Languages : en
Pages : 101

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Book Description
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.

Analysis of Radiation Damaged and Annealed Gallium Arsenide and Indium Phosphide Solar Cells Using Deep Level Transient Spectroscopy

Analysis of Radiation Damaged and Annealed Gallium Arsenide and Indium Phosphide Solar Cells Using Deep Level Transient Spectroscopy PDF Author: Joseph A. Bruening
Publisher:
ISBN:
Category :
Languages : en
Pages : 126

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Book Description
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.

Forward-bias Current Annealing of Radiation Damaged Gallium Arsenide and Silicon Solar Cells

Forward-bias Current Annealing of Radiation Damaged Gallium Arsenide and Silicon Solar Cells PDF Author: Richard L. Staats
Publisher:
ISBN:
Category :
Languages : en
Pages : 100

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Power Recovery of Radiation Damaged MOCVD Grown Indium Phosphide on Silicon Solar Cells Through Argon-ion Laser Annealing

Power Recovery of Radiation Damaged MOCVD Grown Indium Phosphide on Silicon Solar Cells Through Argon-ion Laser Annealing PDF Author: Lynn L. Boyer
Publisher:
ISBN:
Category :
Languages : en
Pages : 133

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Book Description
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).

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 548

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Book Description