HETEROJUNCTION SOLAR CELL BASED ON EPITAXIAL CRYSTALLINE-SILICON THIN FILM ON METALLURGICAL SILICON SUBSTRATE DESIGN

摘要

One embodiment of the present invention provides a heterojunction solar cell. The solar cell includes a metallurgical-grade Si (MG-Si) substrate, a layer of heavily doped crystalline-Si situated above the MG-Si substrate, a layer of lightly doped crystalline-Si situated above the heavily doped crystalline-Si layer, a backside ohmic-contact layer situated on the backside of the MG-Si substrate, a passivation layer situated above the heavily doped crystalline-Si layer, a layer of heavily doped amorphous Si (a-Si) situated above the passivation layer, a layer of transparent-conducting-oxide (TCO) situated above the heavily doped a-Si layer, and a front ohmic-contact electrode situated above the TCO layer.

主权项

1. A solar cell, comprising:
a lightly doped crystalline silicon base layer adapted to generate carriers in response to absorbing light; a heavily doped silicon surface field and barrier layer on a first side of the lightly doped crystalline silicon base layer and adapted to reduce electron-hole recombination at an interface between the lightly doped crystalline silicon base layer and the heavily doped silicon surface field and barrier layer; a passivation layer on a second side of the lightly doped crystalline silicon base layer, wherein the passivation layer comprises intrinsic amorphous silicon, silicon-oxide, or both; a heavily doped amorphous silicon emitter layer adjacent to the passivation layer, wherein a doping type of the heavily doped amorphous silicon emitter layer is opposite to that of the lightly doped crystalline silicon base layer, thereby creating a built-in electrical field which separates the carriers generated in the base layer from light absorption; a transparent-conducting-oxide layer adjacent to the heavily doped amorphous silicon emitter layer as an anti-reflective layer; and an ohmic-contact electrode coupled to the transparent-conducting-oxide layer.