22 documents found, page 1 of 3
Low energy muon study of the p-n interface in chalcopyrite solar cells
Alberto, H. V.; Vilão, R. C.; Ribeiro, E. F. M.; Gil, J. M.; Curado, M. A.; Teixeira, J. P.; Fernandes, P. A.; Cunha, J. M. V.; Salomé, P. M. P.The slow muon technique was used to study the p-n junction of chalcopyrite solar cells. A defect layer near the interface was identi ed and the passivation of the defects by bu er layers was studied. Several cover layers on top of the chalcopyrite Cu(In,Ga)Se2 (CIGS) semiconductor absorber were investigated in this work, namely CdS, ZnSnO, Al2O3 and SiO2. Quantitative results were obtained: The defect layer ext...
Sapphire α−Al2O3 puzzle: Joint μSR and density functional theory study
Vilão, R. C.; Marinopoulos, A. G.; Alberto, H. V.; Gil, J. M.; Lord, J. S.; Weidinger, A.Sapphire (α-Al2O3) has been investigated by the muon spin rotation (µSR) method in several experiments in the past. The main µSR component is a diamagnetic-like signal with a fast relaxation. Because of this diamagnetic-like behavior, the signal was assigned to either positively charged muonium (Mu+) or negatively charged muonium (Mu−), but neither of the two assignments was satisfactory (the so-called “sapphir...
Reply to “Comment on ‘Role of the transition state in muon implantation’ and ‘T...
Vilão, R. C.; Alberto, H. V.; Vieira, R. B. L.; Gil, J. M.; Weidinger, A.
Thermal spike in muon implantation
Vilão, R. C.; Alberto, H. V.; Gil, J. M.; Weidinger, A.
Slow-muon study of quaternary solar-cell materials: Single layers and p-n junct...
Alberto, H. V.; Vilão, R. C.; Vieira, R. B. L.; Gil, J. M.; Weidinger, A.; Sousa, M. G.; Teixeira, J. P.; Cunha, A. F.; Leitão, J. P.; Salomé, P. M. P.
Barrier model in muon implantation and application to Lu2O3
Vilão, Rui; Alberto, Helena; Gil, João; Weidinger, A.; Lichti, R.; Mengyan, P.; Baker, B.; Lord, J.
Slow-muon study of quaternary solar-cell materials: single layers and p−n junct...
Alberto, H. V.; Vilão, R. C.; Vieira, R. B. L.; Gil, J. M.; Weidinger, A.; Sousa, M. G.; Teixeira, J. P.; Cunha, A. F. da; Leitão, J. P.Thin films and p-n junctions for solar cells based on the absorber materials Cu(In,Ga)Se2 and Cu2ZnSnS4 were investigated as a function of depth using implanted low energy muons. The most significant result is a clear decrease of the formation probability of the Mu+ state at the heterojunction interface as well as at the surface of the Cu(In,Ga)Se2 film. This reduction is attributed to a reduced bonding reactio...
The role of the transition state in muon implantation
Vilão, R. C.; Vieira, R. B. L.; Alberto, H. V.; Gil, J. M.; Weidinger, A.In muon-spin-rotation experiments, positive muons are implanted in the material and come to rest in the unrelaxed host lattice. The formation of the final configuration requires a lattice relaxation which does not occur instantly. The present paper is concerned with the transition from the initial stopping state to the final muon configuration. We identify the often observed fast relaxing signal in muon experim...
Isolated hydrogen configurations in zirconia as seen by muon spin spectroscopy ...
Vieira, R. B. L.; Vilão, R. C.; Marinopoulos, A. G.; Gordo, P. M.; Paixão, J. A.; Alberto, H. V.; Gil, J. M.; Weidinger, A.; Lichti, R. L.; Baker, B.
The muonium donor in rutile TiO2 and comparison with hydrogen
Vilão, R. C.; Vieira, R. B. L.; Alberto, H. V.; Gil, J. M.; Weidinger, A.; Lichti, R. L.; Baker, B. B.; Mengyan, P. W.; Lord, J. S.Muonium, a positive muon and an electron, is often used as an experimentally accessible substitute for hydrogen in materials research. In semiconductors and insulators, a large amount of information on the hydrogen behavior is deduced from this analogy; however, it is seldom demonstrated that this procedure is justified. We show here, via a comparison of the hyperfine interactions, that in TiO2 muonium and hydr...