Zone-melting recrystallization for solar cells. Final report, September 1, 1982-August 31, 1984

Technical Report · Fri Aug 31 04:00:00 EDT 1984

OSTI ID:6226513

Smith, H I

Zone-melting recrystallization (ZMR) of Si on SiO/sub 2/ has been investigated to determine if the process can be adapted to produce material configurations suitable for low-cost, high-efficiency photovoltaic cells. In addition, we have demonstrated ZMR of InSb, and begun to establish a practical process for Ge ZMR, with the objective of growing GaAs epitaxially on the Ge. Fundamental recrystallization mechanisms, crystallographic characteristics and electrical properties have been studied. Novel means of controlling crystallographic properties have been developed, including: hourglass, vertical-constriction, entrainment, and orientation-filtering techniques. EBIC studies indicated enhanced dopant diffusion along grain boundaries and subboundaries, and showed that the diffusion length of minority carriers is approx. 100..mu..m. DLTS studies showed that ZMR films do not contain deep levels associated with impurities, and have interface-state densities comparable to IC-grade Si wafers. A (100) crystallographic texture can be achieved in 50..mu..m-thick ZMR Si films using the vertical-constriction technique. Such films can provide a double pass of incident light and should be suitable for high-efficiency photovoltaic cells. Both two-sided and back-contact cells have been fabricated which showed good blue response and modest efficiency. The ZMR process should enable one to produce thick single-crystal Si films directly on the windows of photovoltaic modules. This should lead to practical, low-cost, high-efficiency single crystal cells.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA)
• DOE Contract Number: AC02-82ER13019
• OSTI ID: 6226513
• Report Number(s): DOE/ER/13019-2; ON: DE85004783
• 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
ARSENIC COMPOUNDS
ARSENIDES
BACK CONTACT SOLAR CELLS
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CRYSTALLOGRAPHY
DEEP LEVEL TRANSIENT SPECTROSCOPY
DEPOSITION
DIRECT ENERGY CONVERTERS
EFFICIENCY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELEMENTS
EQUIPMENT
FABRICATION
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
GERMANIUM
INDIUM COMPOUNDS
MELTING
METALS
MICROSCOPY
ORIENTATION
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PHASE TRANSFORMATIONS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PNICTIDES
RECRYSTALLIZATION
SCANNING ELECTRON MICROSCOPY
SILICON COMPOUNDS
SILICON OXIDES
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTRAL RESPONSE
SPECTROSCOPY
SURFACE COATING
ZONE MELTING