Solar cells having ultrathin active layers

Patent · Tue Apr 30 00:00:00 EDT 1985

OSTI ID:5350466

Fan, J C. C.; Bozler, C O

Improvements in solar cells based upon low cost semiconductors, such as amorphous silicon, are disclosed. The improved solar cells of this invention have ultrathin active semiconductor layers having a thickness between 0.1 t /SUB a/ and L /SUB m/ wherein t /SUB a/ is the solar spectrum absorption length and L /SUB m/ is the diffusion length for photogenerated minority charge carriers in the active layer. The back surface reflector has a solar spectrum reflectivity of 70% or greater, so that incident energy not absorbed in a direct pass through the active layer is reflected for another pass. The most preferred embodiment of the cells described herein are shaped to have a light-trapping structure so that light makes mulitple passes through the thin semiconductor layers.

• Assignee: Massachusetts Institute of Technology
• Patent Number(s): US 4514581
• OSTI ID: 5350466
• Resource Relation: Patent File Date: Filed date 8 Nov 1982; Other Information: PAT-APPL-440090
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
SILICON SOLAR CELLS
DESIGN
THICKNESS
ABSORPTIVITY
CHARGE CARRIERS
DIFFUSION LENGTH
FABRICATION
LIGHT TRANSMISSION
REFLECTIVITY
SEMICONDUCTOR MATERIALS
SOLAR REFLECTORS
THIN FILMS
DIMENSIONS
DIRECT ENERGY CONVERTERS
EQUIPMENT
FILMS
LENGTH
MATERIALS
OPTICAL PROPERTIES
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SOLAR CELLS
SOLAR CONCENTRATORS
SOLAR EQUIPMENT
SURFACE PROPERTIES
140501* - Solar Energy Conversion- Photovoltaic Conversion