One-sun, single-crystalline silicon solar cell research

Technical Report · Sat Jun 01 00:00:00 EDT 1991

OSTI ID:5427612

King, R R; Sinton, R A; Swanson, R M ^[1]

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1. Stanford Univ., CA (USA). Solid-State Electronics Lab.

The point-contact solar cell design, the most efficient silicon concentrator solar cell design to date, is explored for use in one-sun applications. The necessary modifications to backside-contact concentrator cell design for operation at one-sun are explored and implemented. Large-area, point-contact solar cells were fabricated on n- and p-type substrates in low-level injection (LLI). The characteristics of these LLI cells were compared to those of four different architectures of cells with substrates in high-level injection (HLI). Both types of cell achieved open-circuit voltages over 700 mV at one-sun, LLI cells had higher fill factors, and HLI cells had substantially higher short-circuit currents. The mechanisms responsible for these observations are discussed. The high V{sub oc} and J{sub sc} of the HLI cells combine to make them more efficient than the LLI cells, with efficiencies measured at Sandia up to 22.7% for a 37.5-cm{sup 2} cell at one sun. This is the highest one-sun efficiency for a silicon cell larger than 4 cm{sup 2}. Simplified, backside-contact solar cell processes were also developed, which have nearly 100% yield. Over 80 such cells, each with a 35-cm{sup 2} area or greater, were delivered to Sandia. Cells made with these simplified processes had efficiencies up to 21.3% for a 37.5-cm{sup 2} cell. The recombination properties of Si{sub 3}N{sub 4} layers over SiO{sub 2} were characterized, since Si{sub 3}N{sub 4} is an excellent antireflection coating for cells laminated under glass. Several prototype flat-plate modules of backside-contact cells were built, with up to 24 cells and efficiencies up to 19%. 26 refs., 16 figs., 4 tabs.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States); Stanford Univ., CA (United States). Solid-State Electronics Lab.
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5427612
• Report Number(s): SAND-91-7003; ON: DE91015646
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
BACK CONTACT SOLAR CELLS
INJECTION
SILICON NITRIDES
ANTIREFLECTION COATINGS
SILICON OXIDES
SILICON SOLAR CELLS
DESIGN
ENERGY EFFICIENCY
FABRICATION
MODIFICATIONS
PASSIVATION
PERFORMANCE TESTING
PHOTOCONDUCTIVITY
PHOTOVOLTAIC CONVERSION
REFLECTIVE COATINGS
REFLECTIVITY
SUBSTRATES
USES
CHALCOGENIDES
COATINGS
CONVERSION
DIRECT ENERGY CONVERSION
DIRECT ENERGY CONVERTERS
EFFICIENCY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY CONVERSION
EQUIPMENT
INTAKE
NITRIDES
NITROGEN COMPOUNDS
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PNICTIDES
SILICON COMPOUNDS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE PROPERTIES
TESTING
140501* - Solar Energy Conversion- Photovoltaic Conversion