Simulation and optimization of single junction a-Si:H solar cell, and for a-Si:H/c-Si tandem solar cells was carried out. Micro-texturing and anti–reflection coating, ARC (silicon nitride) deposition on silicon wafers by PECVD has been performed to reduce the reflection (~7%) from top surface of silicon wafers.ARC (silicon nitride) deposition on 156mm x 156 mm c-silicon wafers has been completed. Single Junction c-Silicon solar cells have been fabricated (Efficiency=11.3%) (Fig. 1). The efficiency is low due to high series resistance in the cells. Neglecting series resistance, estimated efficiency is ~15.5%. Efforts are made to improve the process. Measured I-V curve under AM 1.5G at BHEL, Gurgaon shown in Fig. 2. Process for deposition of indium-tinoxide (ITO) thin films by sputtering for transparent conducting top contact of amorphous silicon top cell of tandem configuration was completed.
Extracted solar cell parameters:
| Parameter | Value |
|---|---|
| Open Circuit Voltage | 0.5460 V |
| Short Circuit Current | 0.2290 A |
| Peak power | 0.090 W |
| Voltage at P peak | 0.4580 V |
| Current at P peak | 0.1980 V |
| Fill factor | 0.73 |
| Cell efficiency | 11.3% |
Fig. 1: Fabricated solar cell
Fig. 2: Measured I-V curve under AM 1.5G at BHEL, Gurgaon