Environmental Engineering Reference
In-Depth Information
Chapter 4
Background of the CdTe Solar Cell and
the New Device Concept
4.1 Introduction
Development of a low-cost thin-film solar cell device with a
reasonable e
ciency for terrestrial solar energy conversion has
beenthesubjectofactiveresearch overthepastthree decades. Two
systems based on CuInGaSe
2
(CIGS) and CdTe absorber materials
are currently under intense research and development worldwide.
CIGS-based solar cells are currently leading with record e
ciencies
of 20.3% [1], whereas CdTe-based solar cells have achieved 16.5%
[2]forsmall-scalelaboratorydevices.TheslowprogressontheCdTe
solar cell research front is noteworthy as it has taken eight years
of worldwide research to increase the e
ciency by only 0.6%, from
15.9% by Britt
et al.
in 1993 [3] to 16.5% [2] by Wu
et al.
in 2001.
This e
ciency figure has been stagnated around 16% since1993.
Although the scientific understanding of material issues and
device physics was slow and lab-scale device e
ciency did not
improve, impressive progress took place in parallel on the scaling-
up and technology front. In commercialisation on the CdTe front,
progress was faster than CIGS solar cells, and Antek, First Solar
