By Topic

Physical concepts for improving solar cells based upon graded CuInGaSe2

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

1 Author(s)
Morales-Acevedo, A. ; Electr. Eng. Dept., Centro de Investig. y de Estudios Av. del IPN, Mexico City

Some basic concepts related to variable band-gap absorbing semiconductors in solar cell structures such as the associated quasi-electric field will be discussed. The effects of this quasi-electric field upon the minority carrier drift-diffusion length and the back surface recombination velocity will cause a larger generated carrier collection with the corresponding increase of the illumination current density. It will also be shown that an additional improvement of the open-circuit voltage is possible when the band-gap is reduced within the space charge region so that the dark saturation current density is reduced there. Our estimation is that in the case of a solar cell where the band-gap reduces from 1.35 eV to 1.15 eV, at the space charge region (of the order of 0.2 mum), an increase of the open-circuit voltage by around 65-70 mV will be observed with respect to the single gap absorbing material case. A similar (increasing) band-gap variation in the bulk of the material will cause an increase of the drift-diffusion length of minority carriers by a factor of 4 with respect to a single band-gap material. Therefore, based on these physical concepts, two possible structures with variable band-gap CIGS layers are proposed in order to have higher efficiencies than for cells without any band-gap grading.

Published in:

Electrical Engineering, Computing Science and Automatic Control, 2008. CCE 2008. 5th International Conference on

Date of Conference:

12-14 Nov. 2008