Amorphous thin films for solar-cell applications. Final report, 11 September 1979-10 September 1980

Technical Report · Wed Oct 01 04:00:00 EDT 1980

OSTI ID:6662732

Carlson, D E; Crandall, R S; Dresner, J; Goldstein, B; Hanak, J J; Moore, A R; Schade, H E; Staebler, D L; Weakliem, H A

The drift mobility has been measured in doped amorphous silicon by measuring the current transient in a Schottky-barrier device during a reverse-bias voltage pulse. The drift mobility is approx. 6.5 x 10/sup -3/ cm/sup 2//V-s at room temperature. Mass spectroscopy studies indicate that the film growth cannot be a simple ion-surface recombination process but is probably due to either thermal decomposition of higher silanes or free radical-surface reaction. The photoelectromagnetic effect has been used to measure the hole diffusion length in undoped a-Si:H. Another technique that has been recently developed at RCA involves surface photovoltage profiling of solar-cell structures. This technique involves the use of a vibrating probe in conjunction with an argon sputtering beam to probe the field distribution of p-i-n cells. Preliminary measurements of the Hall effect in p-type a-Si:H yield a value of approx. 2 x 10/sup -2/ cm/sup 2/ /V-s at 100/sup 0/C with an activation energy of 0.45 eV. Electron irradiation studies show that the threshold energy for electron bombardment damage is more than 10/sup 2/X less than in crystalline Si. A detailed study of the effects of adding various fluorine-containing gases (SiF/sub 4/, HF and F/sub 2/) to silane discharges showed that the device performance is adversely affected. A detailed description of an experimental optimization technique for both a-Si:H materials and solar cells is given. This technique utilizes samples made with graded deposition conditions and characterized with automated testing equipment. These procedures have helped to develop two different types of p-i-n solar cells with conversion efficiencies in the 5 to 6% range. It was shown that interference fringes in the collection efficiency of a-Si:H solar cells can give useful information concerning the transport in gap states.

• Research Organization: RCA Labs., Princeton, NJ (USA)
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 6662732
• Report Number(s): SERI/PR-0-8254-F
• 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
DEPOSITION
DIFFUSION LENGTH
DIMENSIONS
DIRECT ENERGY CONVERTERS
EFFICIENCY
ELECTRIC DISCHARGES
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
EQUIPMENT
FABRICATION
FERMIONS
FILMS
FLUORINE ADDITIONS
GLOW DISCHARGES
GRAPHS
HALL EFFECT
HOLES
HYDROGEN ADDITIONS
INFORMATION
LENGTH
LEPTONS
MATHEMATICAL MODELS
MOBILITY
PERFORMANCE
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL RADIATION EFFECTS
PLASMA ARC SPRAYING
RADIATION EFFECTS
RESEARCH PROGRAMS
SEMIMETALS
SILICON
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTRAL RESPONSE
SPRAY COATING
SURFACE COATING