Amorphous thin films for solar-cell applications. Quarterly report No. 2, 11 December 1979-10 March 1980

Technical Report · Sat Mar 01 04:00:00 EST 1980

DOI:https://doi.org/10.2172/5250553· OSTI ID:5250553

Carlson, D. E.; Crandall, R. S.; Dresner, J.; Goldstein, B.; Hanak, J. J.; Moore, A. R.; Pankove, J. I.; Weakliem, H. A.

Measurements of both primary and secondary photocurrents for photon energies between 0.58 and 2.0 eV in a-Si:H solar-cell structures have been used to provide information about the density of states above the valence band as well as show that holes are mobile deep in the bandgap. The drift mobility is independent of excitation energy, indicating that the majority carriers are excited to the same states, irrespective of the excitation energy. Deposition studies in the dc proximity system have shown that the conductivity and photoconductivity of doped films (both boron- and phosphorus-doped) increase with substrate temperature. Mass spectroscopy studies have shown that the larger Si/sub x/H/sub y//sup +/ clusters are favored by operating rf discharges at low rf powers and high pressures. The Hall mobility is roughly constant below 360 K but exhibits a thermal activation energy of approx. 0.13 eV at higher temperatures. These observations rule out simple extended-state transport as the conduction mechanism. The photoelectromagnetic effect has been used to estimate the hole lifetime (approx. 3.4 x 10/sup -7/s) in undoped a-Si:H; the electron lifetime is approx. 1.7 x 10/sup -6/s. An a-Si:H monolithic solar panel consisting of 16 cells in series has been fabricated on a 4'' x 4'' glass substrate (63 cm/sup 2/ of active area), and the panel exhibits a conversion efficiency of 3.6%. In another series of experiments, the thicknesses and doping levels of p-i-n cells made in a dc(P) discharge were optimized. The best cell made in these experiments had an efficiency of 5.3% with an area of 1.19 cm/sup 2/.

• Research Organization: RCA Labs., Princeton, NJ (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 5250553
• Report Number(s): SERI/PR-8254-1-T2
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
AMORPHOUS STATE
CARRIER MOBILITY
DATA
DATA FORMS
DEPOSITION
DIRECT ENERGY CONVERTERS
ELEMENTS
ENERGY GAP
EQUIPMENT
FABRICATION
GRAPHS
HALL EFFECT
INFORMATION
LUMINESCENCE
MASS SPECTROSCOPY
MATHEMATICAL MODELS
MOBILITY
OPTIMIZATION
PERFORMANCE
PHOTOELECTRIC CELLS
PHOTOLUMINESCENCE
PHOTOVOLTAIC CELLS
RESEARCH PROGRAMS
SEMIMETALS
SILICON
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTROSCOPY
SUBSTRATES
TEMPERATURE EFFECTS