A NEW TYPE OF HIGH-EFFICIENCY WITH A LOW-COST SOLAR-CELL HAVING THE STRUCTURE OF A MU-C-SIC POLYCRYSTALLINE SILICON HETEROJUNCTION

A new type of high-efficiency solar cell has been developed by a simple production process only with electron cyclotron resonance plasma-assisted chemical vapor deposition of highly conductive microcrystalline silicon carbide (μ c -SiC) on polycrystalline silicon (poly-Si). The device consists of a p -type μ c -SiC/ n -type poly-Si heterojunction where the window material is a specially made wide-band gap and highly conductive μ c -SiC. At the present stage, a conversion efficiency of 15.4% with Voc=556 mV, J sc=35.7 mA/cm2, and F. F.=77.4% has been achieved. Also employing this device as a bottom cell in a four-terminal amorphous silicon (a -Si) tandem-type solar cell, 16.8% efficiency has been obtained. A series of technical data on the fabrication technology and device performance is presented and discussed.