Research on amorphous silicon-germanium alloys for tandem solar cells: Annual subcontract report, 1 July 1986--31 August 1987

Technical Report · Sun May 01 04:00:00 EDT 1988

OSTI ID:6914592

Paul, W; Mackenzie, K D

The objective of this work is to explore the deposition conditions necessary to produce amorphous Si-Ge alloys with a band gap near 1.3 to 1.4 eV whose photo-electronic properties will be comparable to those of a-Si:H. It is essential to understand why the photoconductivity of a-Si/sub 1-x/Ge/sub x/:H:F is superior to that of a-Si/sub 1-x/Ge/sub x/:H, while most of the commonly measured optical and electronic properties remain unchanged. The focus of this investigation was on deposition conditions and on the microstructure of the films as revealed by transmission electron microscopy, gas evolution, and differential scanning calorimetry, concentrating on alloys with a high Ge content. Films were made both by glow discharge and by photochemical vapor deposition in a new type of apparatus. Structure, very important in determining photoelectronic properties, depends on the totality of the deposition parameter, and it is therefore important to understand the conditions in the plasma and at the interface of the growing film, when SiH/sub 4/, GeH/sub 4/, and H/sub 2/ are present in different concentrations, whatever the method of deposition. 3 refs., 8 figs., 2 tabs.

• Research Organization: Solar Energy Research Inst., Golden, CO (USA); Harvard Univ., Cambridge, MA (USA). Div. of Applied Sciences
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6914592
• Report Number(s): SERI/STR-211-3351; ON: DE88001168
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
ALLOYS
AMORPHOUS STATE
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CRYSTAL STRUCTURE
DEPOSITION
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY GAP
EQUIPMENT
FILMS
GERMANIUM ALLOYS
MICROSTRUCTURE
PHOTOCONDUCTIVITY
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PROGRESS REPORT
RESEARCH PROGRAMS
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING
TEMPERATURE DEPENDENCE
THIN FILMS