Optimization of transparent and reflecting electrodes for amorphous silicon solar cells

Technical Report · Fri Feb 01 00:00:00 EST 1991

OSTI ID:6083916

Gordon, R G; Hu, Jianhua; Musher, J; Giunta, C ^[1]

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1. Harvard Univ., Cambridge, MA (USA). Dept. of Chemistry

The specific objectives of this research are to: (1) Deposit and characterize textured zinc oxide with improved conductivities (less than 8 ohms/square sheet resistance) and optical transmission (greater than 85% for 450 to 700 nm), for use as front and back contacts in hydrogenated amorphous silicon p-i-n devices. Study the surface morphology of zinc oxide films deposited by chemical vapor deposition at atmospheric pressure (APCVD), their crystallite sizes, shapes and orientations, and their nucleation (early growth) as a function of chemical precursors and reaction conditions. Optimize the growth process to produce structures that provide good light trapping in an amorphous silicon film deposited on the zinc oxide film. The films must have good adhesion to glass substrates. (2) Study the deposition rate of zinc oxide films as a function of temperature, and concentration and types of reactants. Maximize the growth rate, subject to the conditions of maintaining satisfactory film properties, including high transparency (85%), high conductivity (8 ohm/square sheet resistance), and good light trapping. (3) Develop techniques for deposition of fluorinated zinc oxide films by APCVD on amorphous silicon films in the temperature range of 250-280C for use as back contacts. (4) Deposit titanium nitride films at a temperature of about 250C by APCVD on amorphous silicon as diffusion barrier, and then deposit highly reflective metals such as aluminum or silver. Anneal samples and test for metal diffusion through the TiN into the silicon. Optimize the TiN film for minimum diffusion consistent with maintaining desirable TiN film properties. (5) Incorporate the front and back contacts including the TiN barrier layer developed under this research into amorphous silicon p-i-n devices and determine the film parameters that provide the greatest improvement in the device solar energy conversion efficiency. 23 refs., 18 figs., 2 tabs.

• Research Organization: Solar Energy Research Inst., Golden, CO (USA); Harvard Univ., Cambridge, MA (USA). Dept. of Chemistry
• Sponsoring Organization: USDOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6083916
• Report Number(s): SERI/TP-214-4141; ON: DE91002132
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
SILICON SOLAR CELLS
SEMICONDUCTOR MATERIALS
TITANIUM NITRIDES
CHEMICAL VAPOR DEPOSITION
ELECTRICAL PROPERTIES
OPTICAL PROPERTIES
ZINC OXIDES
ABSORPTION
ALUMINIUM
ATMOSPHERIC PRESSURE
CRYSTAL GROWTH
DIFFUSION
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRODES
ELECTRON DENSITY
ELECTRON MOBILITY
FILMS
FLUORINE
GLASS
INFRARED RADIATION
LIGHT TRANSMISSION
PROGRESS REPORT
QUANTITY RATIO
REFLECTIVITY
ROUGHNESS
SCANNING ELECTRON MICROSCOPY
SILVER
TEMPERATURE DEPENDENCE
TEXTURE
THICKNESS
VISIBLE RADIATION
X-RAY DIFFRACTION
CHALCOGENIDES
CHEMICAL COATING
COHERENT SCATTERING
DEPOSITION
DIFFRACTION
DIMENSIONS
DIRECT ENERGY CONVERTERS
DOCUMENT TYPES
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELEMENTS
EQUIPMENT
HALOGENS
MATERIALS
METALS
MICROSCOPY
MOBILITY
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE MOBILITY
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PNICTIDES
RADIATIONS
SCATTERING
SOLAR CELLS
SOLAR EQUIPMENT
SURFACE COATING
SURFACE PROPERTIES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZINC COMPOUNDS
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture
360603 - Materials- Properties