resumo
We investigated bulk and thin-film samples of the quaternary p-type semiconductor Cu2ZnSnS4 (CZTS) by,u,SR, in order to characterize the existing muonium signals. We find that the majority of the implanted muons form a diamagnetic state broadened by an interaction with the Cu nuclear moments, which we interpret as Mu(+) bound to sulphur. A paramagnetic fraction is also present at low temperatures and the ratio between the two muon charge states, Mu(+) and Mu(0), varies between 20 and 40% prior to the onset of muon diffusion, which occurs at around 150 K. The fraction of Mu(0) is found to be sensitive to the defect content of the sample. The paramagnetic fraction has two different contributions and their origin is discussed and related with the muon role as a probe for charge carriers in the material.
palavras-chave
HYDROGEN; OXIDE; PSI
categoria
Physics
autores
Alberto, HV; Vila, RC; Gil, JM; Duarte, JP; Vieira, RBL; Weidinger, A; Leitao, JP; da Cunha, AF; Sousa, MG; Teixeira, JP; Fernandes, PA; Salome, PMP; Timmo, K; Loorits, M; Amato, A; Luetkens, H; Prokscha, T; Suter, A; Salman, Z
nossos autores
Ricardo Vieira
Investigadoragradecimentos
This work was supported from funds from FEDER ( Programa Operacional Factores de Competitividade COMPETE) and from FCT - Fundacao para a Ciencia e Tecnologia - under the project PEst- OE. FIS. UI0036.2014 and through Grants PTDC/ CTM- MET/ 113486/ 2009, PEST- C/ CTM/ LA0025/ 2011 and RECI/ FIS- NAN/ 0183/ 2012.