Prathapa, P. and Bartringera, J. and Slaoui, A. (2014) Analysis of laser doping of silicon using different boron dopant sources. Applied Surface Science , 302. pp. 286-274. ISSN 0169-4332

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Abstract

Implementation of selective emitter that decouples the requirements for front doping and metallization leads to improve the efficiency of crystalline silicon solar cells. Formation of such an efficient selective emitter using a laser beam with a suitable wavelength is an attractive method. The present work focuses on the analysis of laser doping of boron using different finite sources such as borosilicate glass (BSG) deposited by PECVD, spin-on solution and BCl3 gas source. KrF excimer laser (248 nm) was used for the selective doping. The surface dopant concentration and depth, as measured using SIMS, were controlled by variation of the laser fluence, pulse number and dopant source thickness. Depending on the type of BSG source, sheet resistance close to 20 Omega/sq was achieved at the laser fluences in the range,2.5-5 J/cm(2). The PECVD-BSG layers with a relatively higher thickness resulted in a lower sheet resistance of 20 Omega/sq with a junction of depth of similar to 1 mu m at a moderate laser fluence of 2.5 J/cm(2). In the case of BSG deposited by spin-on source, a deeper junction of depth of similar to 2.7 mu m with a plateau profile of 1 mu m was formed at a laser fluence of 3.1 j/cm(2) that resulted in a lower sheet resistance of similar to 31 Omega/sq. Redistribution of the dopant with pulse repetition was observed for the BSG deposited by BCl3 gas source. Pulse repetition at relatively lower laser fluences (>threshold energy) resulted in the best electrical results in combination with a limited laser induced damage in the silicon crystal. Also, multiple laser annealing resulted in redistribution of the dopant profiles in terms of enhanced junction depth.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/S Elsevier.
Uncontrolled Keywords:	Laser doping Selective emitter Silicon solar cells
Subjects:	Acoustics Chemistry Materials Science
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	09 Sep 2015 06:28
Last Modified:	09 Sep 2015 06:28
URI:	http://npl.csircentral.net/id/eprint/1164

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