High-efficiency silicon solar-cell design and practical barriers
A numerical evaluation technique is used to study the impact of practical barriers, such as heavy doping effects (Auger recombination, band gap narrowing), surface recombination, shadowing losses and minority-carrier lifetime (tau), on a high efficiency silicon solar cell performance. A hypothetical case, considering only radiative recombination losses and ignoring technology limited and fundamental losses is evaluated to estimate highest efficiency. Considering a high tau of 1 ms, efficiency of a silicon solar cell of the hypothetical case is estimated to be around 29%. This is comparable with (detailed balance limit) maximum efficiency of a p-n junction solar cell of 30%, estimated by Shockley and Queisser. Value of tau is varied from 1 second to 20 ..mu..s. Heavy doping effects, and realizable values of surface recombination velocities and shadowing, are then considered in succession and their influence on cell efficiency is evaluated and quantified. It is shown that these practical barriers cause the cell efficiency to reduce from the maximum value of 29% to the experimentally achieved value of about 19%. Improvement in open circuit voltage (V/sub oc/) is required to achieve cell efficiency greater than 20%. Increased value of tau reduces reverse saturation current and, hence, improves V/sub oc/. Control of surface recombination losses becomes critical at higher V/sub oc/. Substantial improvement in tau and considerable reduction in surface recombination velocities is essential to achieve cell efficiencies greater than 20%. Lack of available data for minority-carrier mobility, heavy doping effect, tau in thin emitters, surface recombination velocities, etc., are discussed. Limitations of one dimensional numerical analysis for considering two- and three-dimensional cell designs, such as floating emitter and dot junction cells, are pointed out.
- Research Organization:
- Jet Propulsion Lab., Pasadena, CA (USA)
- DOE Contract Number:
- AI01-76ET20356
- OSTI ID:
- 6056173
- Report Number(s):
- DOE/JPL/1012-112; JPL-PUB-85-75; ON: DE86010242
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
High-efficiency silicon solar-cell design evaluation and sensitivity analysis
Development of high-efficiency solar cells on silicon web. Fourth quarterly progress report, January-March 1985
Related Subjects
SILICON SOLAR CELLS
COMPUTERIZED SIMULATION
CONSTRAINTS
DESIGN
CARRIER LIFETIME
PERFORMANCE
RECOMBINATION
DIRECT ENERGY CONVERTERS
EQUIPMENT
LIFETIME
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SIMULATION
SOLAR CELLS
SOLAR EQUIPMENT
140501* - Solar Energy Conversion- Photovoltaic Conversion