Working together through NREL's
Thin Film PV Partnership Program, ITN/Energy Systems
(ITN/ES) of Wheat Ridge, CO, and Colorado School
of Mines (CSM) of Golden, CO, have jointly fabricated
the world's first 10.6% thin-film CdTe solar cell
using the atmospheric-pressure chemical vapor deposition
method (APCVD). The thin-film CdTe solar cell structure
is glass/SnO2 /CdS/ CdTe/ contact. The cell parameters
are Jsc = 21.1 mA/cm2,Voc = 0.79, FF = 0.64, and Eff
= 10.6%.
Advantages
There were several cells in the
efficiency range of 9.8% to 10.6%. The advantage of
the APCVD process is that it does not have load-locks,
which add to the cost of the deposition system. NREL
scientist Sally Asher and her co-workers, who specialize
in static SIMS (secondary ion mass spectroscopy),
have helped ITN/ES and CSM reach this important milestone.
SIMS analysis had identified high O2 content (about
30%) caused from leaks in the APCVD system, which
was detrimental to device performance. With further
optimization of the processing and device design should
approach a solar cell efficiency of 12.0% in the near
future.
