Title :
Role of i-aSi:H Layers in aSi:H/cSi Heterojunction Solar Cells
Author :
Hayashi, Yasuhiro ; Debin Li ; Ogura, Akira ; Ohshita, Yoshio
Author_Institution :
Semicond. Lab., Toyota Technol. Inst., Nagoya, Japan
Abstract :
The dependence of solar cell parameters on i-aSi:H (non- or lightly-doped hydrogenated amorphous silicon) layer thickness in an aSi:H/cSi (crystalline silicon) heterojunction solar cell was analyzed using numerical simulation. By considering the quantum confinement effect at interfaces between i-aSi:H and cSi, experimental data which had not been explained by simulation could be successfully interpreted. The mechanism of an open-circuit voltage increase was visually presented by analyzing carrier distributions and quasi-Fermi levels near cSi surfaces and in the i-aSi:H layers. The optimized thicknesses of the i-aSi:H layers in both front and rear junctions were suggested to obtain the maximum conversion efficiency. The influences of the quantum confinement effect on the simulation results were discussed.
Keywords :
Fermi level; amorphous semiconductors; elemental semiconductors; hydrogen; numerical analysis; semiconductor device models; semiconductor heterojunctions; silicon; solar cells; Si:H-Si; aSi:H/cSi heterojunction solar cells; cSi surfaces; carrier distributions; front junction; i-aSi:H layer thickness; maximum conversion efficiency; numerical simulation; open-circuit voltage; optimized thicknesses; quantum confinement effect; quasiFermi levels; rear junction; solar cell parameters; Amorphous silicon; Crystalline materials; Heterojunctions; Indium tin oxide; Mathematical model; Photovoltaic cells; Short-circuit currents; Substrates; Accumulation layer; conversion efficiency; crystalline silicon; fill factor; heterojunction; hydrogenated amorphous silicon; inversion layer; open-circuit voltage; quantum confinement; short-circuit current; solar cell;
Journal_Title :
Photovoltaics, IEEE Journal of
DOI :
10.1109/JPHOTOV.2013.2274616
