Title :
Resetting the defect chemistry in CdTe
Author :
Wyatt K. Metzger;James Burst;David Albin;Eric Colegrove;John Moseley;Joel Duenow;Stuart Farrell;Helio Moutinho;Matt Reese;Steve Johnston;Teresa Barnes;Craig Perkins;Harvey Guthrey;Mowafak Al-Jassim
Author_Institution :
National Renewable Energy Laboratory, Golden, CO, 80401, USA
fDate :
6/1/2015 12:00:00 AM
Abstract :
CdTe cell efficiencies have increased from 17% to 21% in the past three years and now rival polycrystalline Si [1]. Research is now targeting 25% to displace Si, attain costs less than 40 cents/W, and reach grid parity. Recent efficiency gains have come largely from greater photocurrent. There is still headroom to lower costs and improve performance by increasing open-circuit voltage (Voc) and fill factor. Record-efficiency CdTe cells have been limited to Voc <; 880 mV, whereas GaAs can attain Voc of 1.10 V with a slightly smaller bandgap [2,3]. To overcome this barrier, we seek to understand and increase lifetime and carrier concentration in CdTe. In polycrystalline structures, lifetime can be limited by interface and grain-boundary recombination, and attaining high carrier concentration is complicated by morphology.
Keywords :
"Cadmium compounds","II-VI semiconductor materials","Photovoltaic cells","Films","Chlorine","Silicon"
Conference_Titel :
Photovoltaic Specialist Conference (PVSC), 2015 IEEE 42nd
DOI :
10.1109/PVSC.2015.7356444