Electrical and optical activities of small angle grain boundaries in multicrystalline Si

Abstract

We have characterized the electrical and optical activities of small grain boundaries (SA-GBs) by using electron-beam-induced current (EBIC) and cathodoluminescence (CL). EBIC observation at room temperature indicates that the SA-GBs are grouped into two categories. SA-GBs with misorientation angle lower than 1° shows lower EBIC contrast like <10%, named as "general". Those with 2-3° have higher contrast more than 20%, named as "special". At 100 K, all the SA-GBs become visible and their contrast increases. On the other hand, CL observation at 15 K shows that general SA-GBs show D3 and D4, while special ones show D1 and D2. We explained these properties of SA-GBs in terms of dislocation model. General SA-GBs are regarded as the ensemble of individual dislocations. Special SA-GBs are composed of the densely aligned dislocations in which dislocation interaction takes place. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.