Optimization of interdigitated back contact silicon heterojunction solar cells by two-dimensional numerical simulation

Conference · Tue Jun 09 00:00:00 EDT 2009

OSTI ID:963898

Lu, Meijun; Das, Ujjwal; Bowden, Stuart; Hegedus, Steven; Birmire, Robert

In this paper, two-dimensional (2D) simulation of interdigitated back contact silicon heterojunction (IBC-SHJ) solar cells is presented using Sentaurus Device, a software package of Synopsys TCAD. A model is established incorporating a distribution of trap states of amorphous-silicon material and thermionic emission across the amorphous-silicon / crystalline-silicon heterointerface. The 2D nature of IBC-SHJ device is evaluated and current density-voltage (J-V) curves are generated. Optimization of IBC-SHJ solar cells is then discussed through simulation. It is shown that the open circuit voltage (VOC) and short circuit current density (JSC) of IBC-SHJ solar cells increase with decreasing front surface recombination velocity. The JSC improves further with the increase of relative coverage of p-type emitter contacts, which is explained by the simulated and measured position dependent laser beam induced current (LBIC) line scan. The S-shaped J-V curves with low fill factor (FF) observed in experiments are also simulated, and three methods to improve FF by modifying the intrinsic a-Si buffer layer are suggested: (i) decreased thickness, (ii) increased conductivity, and (iii) reduced band gap. With all these optimizations, an efficiency of 26% for IBC-SHJ solar cells is potentially achievable.

• Research Organization: University of Delaware, Newark, DE
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy (EE); USDOE EERE Office of Solar Energy Technology (EE-2A)
• DOE Contract Number: FG36-08GO18077
• OSTI ID: 963898
• Report Number(s): DOE/GO/18077; TRN: US201110%%192
• Resource Relation: Conference: 34th IEEE PVSC, Philadelphia, PA, June 2009
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
BUFFERS
CURRENT DENSITY
DISTRIBUTION
EFFICIENCY
ELECTRIC POTENTIAL
ELECTRICAL FAULTS
FILL FACTORS
HETEROJUNCTIONS
LASERS
OPTIMIZATION
ORGANIC COMPOUNDS
RECOMBINATION
SILICON
SIMULATION
SOLAR CELLS
THERMIONIC EMISSION
THICKNESS
VELOCITY
VOLATILE MATTER
silicon
heterojunction
solar cells
interdigitated back contact