Pioneer in silicon photovoltaics: Materials to Device………1974 onwards

Silicon Solar Cells Group at CSIR-NPL is the oldest photovoltaic group and has very rich history in silicon based photovoltaics since last four decades. We were the first to develop silicon solar cells in the country in around mid 70’s. CSIR-NPL is the first laboratory to demonstrate the complete process ‘from metallurgical grade silicon to solar grade poly silicon, fabrication of solar cells and solar penal running a water pump.

Raw Material	Slim Silicon Rod	CVD Reactor	Small Water pump run by solar penal, 1980

Research Activities

Currently, the group is actively involved in CSIR Energy Program ‘Technologies And Products for Solar Energy Utilization through Networks (TAPSUN)’ for the improvement of silicon solar cell efficiency to make silicon photovoltaic economically viable. The group has following prime aims for the improvement of crystalline silicon solar cell efficiency.

• Emitter engineering using selective emitter concept for silicon solar cells,
• Surface passivation schemes to reduce the surface recombination velocity,
• Surface modification schemes to reduce reflection losses,
• Metal contacts improvement;

Besides, the group is also involved in test and measurement of the photovoltaic devices. It has expertise and knowledge in fabrication, measurements, characterization, and theory to support photovoltaic (PV) research and development (R&D).

Current R&D highlights

Facilities

The group is well equipped with several state of the art facilities for crystalline silicon solar cell fabrication and PV materials and device characterization.

A. Silicon solar cells processing:

• 3 sets of diffusion/oxidation furnaces (up to 4 inch wafers processing)
• ALD (Thermal and plasma assisted, PICOSUN)
• RTP (AnnealSys, AS-One 150, France)
• Laser Scriber (Yuhan Sonic, China)

B. Test & Measurement of PV devices:

• I-V measurement system with Class AAA Sun Simulator (21x21 cm2, AM1 & AM1.5 solar spectrum) (Newport/Oriel)
• SR and I-V tester (CEP-25HS-50SR Japan) (5x5 cm2)
• Non-contact measurements (m-PCD, SPV, LBIC) (Semilab, WT 2000 P) ,
• Sinton’s Lifetime tester and Sun Voc measurement set up
• Four Point Probe (Quad Pro, Lucas USA)