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EP 2 647 060 A2

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(88) Date of publication A3: 29.11.2012 (43) Date of publication: 09.10.2013 Bulletin 2013/41 (21) Application number: 11826188.2 (22) Date of filing: 30.11.2011

(51) International Patent Classification (IPC):  H01L 31/12(2006.01) H01L 33/00(2010.01) H01L 51/50(2006.01) H01L 31/16(2006.01) H01L 33/34(2010.01) G02B 6/42(2006.01) (86) International application number: PCT/ZA2011/000090 (87) International publication number: WO 2012/075511 (07.06.2012 Gazette 2012/23)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (30) Priority: 30.11.2010 ZA 201008577 30.11.2010 ZA 201008579 23.12.2010 ZA 201006804 23.12.2010 ZA 201006803 25.05.2011 ZA 201103826 05.08.2011 ZA 201105761 29.09.2011 ZA 201107103 (71) Applicant: Tshwane University Of Technology 0183 Pretoria West (ZA)

(72) Inventor: SNYMAN, Lukas, Willem 0081 Pretoria (ZA) (74) Representative: Baur & Weber Patentanwälte  Rosengasse 13 89073 Ulm 89073 Ulm (DE)