48 documents found, page 1 of 5
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...
Cu(In,Ga)Se2 based ultrathin solar cells the pathway from lab rigid to large sc...
Lopes, T. S.; Teixeira, J. P.; Curado, M. A.; Ferreira, B. R.; Oliveira, A. J. N.; Cunha, J. M. V.; Monteiro, M.; Violas, A.; Barbosa, J. R. S.The incorporation of interface passivation structures in ultrathin Cu(In,Ga)Se2 based solar cells is shown. The fabrication used an industry scalable lithography technique—nanoimprint lithography (NIL)—for a 15 × 15 cm2 dielectric layer patterning. Devices with a NIL nanopatterned dielectric layer are benchmarked against electron-beam lithography (EBL) patterning, using rigid substrates. The NIL patterned devic...
Cu(In,Ga)Se2 based ultrathin solar cells the pathway from lab rigid to large sc...
Lopes, T. S.; Teixeira, J. P.; Curado, M. A.; Ferreira, B. R.; Oliveira, A. J. N.; Cunha, J. M. V.; Monteiro, M.; Violas, A.; Barbosa, J. R. S.The incorporation of interface passivation structures in ultrathin Cu(In,Ga)Se2 based solar cells is shown. The fabrication used an industry scalable lithography technique—nanoimprint lithography (NIL)—for a 15 × 15 cm2 dielectric layer patterning. Devices with a NIL nanopatterned dielectric layer are benchmarked against electron-beam lithography (EBL) patterning, using rigid substrates. The NIL patterned devic...
Cu(In,Ga)Se2 based ultrathin solar cells the pathway from lab rigid to large sc...
Lopes, T.S.; Teixeira, J. P.; Curado, M. A.; Ferreira, B. R.; Oliveira, A. J. N.; Cunha, J. M. V.; Monteiro, M.; Violas, A.; Barbosa, J. R. S.The incorporation of interface passivation structures in ultrathin Cu(In,Ga)Se2 based solar cells is shown. The fabrication used an industry scalable lithography technique—nanoimprint lithography (NIL)—for a 15 × 15 cm2 dielectric layer patterning. Devices with a NIL nanopatterned dielectric layer are benchmarked against electron-beam lithography (EBL) patterning, using rigid substrates. The NIL patterned devic...
Electronic Conduction Mechanisms and Defects in Polycrystalline Antimony Selenide
Cifuentes, N.; Ghosh, Santunu; Shongolova, A.; Correia, M. R.; Salomé, P. M. P.; Fernandes, P. A.; Ranjbar, S.; Garud, S.; Vermang, B.; Ribeiro, G. M.A study of the electronic conduction mechanisms and electrically active defects in polycrystalline Sb2Se3 is presented. It is shown that for temperatures above 200 K, the electrical transport is dominated by thermal emission of free holes, ionized from shallow acceptors, over the intergrain potential barriers. In this temperature range, the temperature dependence of the mobility of holes, limited by the intergr...
Encapsulation of Nanostructures in a Dielectric Matrix Providing Optical Enhanc...
Oliveira, Antonio; de Wild, Jessica; Oliveira, Kevin; Valença, Beatriz A.; Guerreiro, Joana Rafaela; Abalde-Cela, Sara; Lopes, TomásThe incorporation of nanostructures in optoelectronic devices for enhancing their optical performance is widely studied. However, several problems related to the processing complexity and the low performance of the nanostructures have hindered such actions in real-life devices. Herein, a novel way of introducing gold nanoparticles in a solar cell structure is proposed in which the nanostructures are encapsulate...
Front passivation of Cu(In,Ga)Se2 solar cells using Al2O3: culprits and benefits
Curado, M. A.; Teixeira, J. P.; Monteiro, M.; Ribeiro, E. F. M.; Vilão, R.C.; Alberto, H. V.; Cunha, J. M. V.; Lopes, T.S.; Oliveira, K.In recent years, the strategies used to break the Cu(In,Ga)Se2 (CIGS) world record of light to power conversion efficiency, were based on improvements of the absorber optoelectronic and crystalline properties, mainly using complex post-deposition treatments. To reach even higher efficiency values, advances in the solar cell architecture are needed focusing in the CIGS interfaces. In this study, we evaluate the ...
Recombination channels in Cu(In,Ga)Se2 thin films: impact of the Ga-profile
Teixeira, J. P.; Vieira, R. B. L.; Falcão, B. P.; Edoff, M.; Salomé, P. M. P.; Leitão, J. P.Depth bandgap profiles via a [Ga]/([Ga]+[In]) variation in the Cu(In,Ga)Se2 (CIGS) absorber layer have been implemented as a strategy to enhance the performance of CIGS solar cells. Since the [Ga]/([Ga]+[In]) determines to a large extent the position of the conduction band minimum, different Ga-profiles lead to different electronic energy levels structures throughout the CIGS layer. In this paper, from the inve...
Muon implantation experiments in films: obtaining depth-resolved information
Simões, A. F. A.; Alberto, H. V.; Vilão, R. C.; Gil, J. M.; Cunha, J. M. V.; Curado, M. A.; Salomé, P. M. P.; Prokscha, T.; Suter, A.; Salman, Z.Implanted positive muons with low energies (in the range 1-30 keV) are extremely useful local probes in the study of thin films and multi-layer structures. The average muon stopping depth, typically in the order of tens of nanometers, is a function of the muon implantation energy and of the density of the material, but the stopping range extends over a broad region, which is also in the order of tens of nanomet...
Electronic conduction mechanisms and defects in polycrystalline antimony selenide
Cifuentes, N.; Ghosh, S.; Shongolova, A.; Correia, M. R.; Salomé, P. M. P.; Fernandes, P. A.; Ranjbar, S.; Garud, S.; Vermang, B.; Ribeiro, G. M.A study on the electronic conduction mechanisms and electrically active defects in polycrystalline Sb2Se3 is presented. It is shown that, for temperatures above 200 K the electrical transport is dominated by thermal emission of free holes, ionized from shallow acceptors, over the inter-grain potential barriers. The temperature dependence of the holes mobility, limited by the inter-grain potential barriers, is t...