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Browsing by Author "Oliveira, Antonio J. N."

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  • Decoupling of Optical and Electrical Properties of Rear Contact CIGS Solar Cells
    Publication . Cunha, Jose M. V.; Fernandes, P. A.; Salome, Pedro M. P.; Lopes, Tomas S.; Bose, Sourav; Hultqvist, Adam; Chen, Wei-Chao; Donzel-Gargand, Olivier; Ribeiro, Rodrigo M.; Oliveira, Antonio J. N.; Edoff, Marika
    A novel architecture that comprises rear interface passivation and increased rear optical reflection is presented with the following advantages: i) enhanced optical reflection is achieved by the deposition of a metallic layer over the Mo rear contact; ii) improved interface quality with CIGS by adding a sputtered Al 2 O 3 layer over the metallic layer; and, iii) optimal ohmic electrical contact ensured by rear-openings refilling with a second layer of Mo as generally observed from the growth of CIGS on Mo. Hence, a decoupling between the electrical function and the optical purpose of the rear substrate is achieved. We present in detail the manufacturing procedure of such type of architecture together with its benefits and caveats. A preliminary analysis showing an architecture proof-of-concept is presented and discussed.
    2019Journal article Restricted access Show more
  • SiOx Patterned Based Substrates Implemented in Cu(In,Ga)Se2 Ultrathin Solar Cells: Optimum Thickness
    Publication . Oliveira, Kevin; Teixeira, Jennifer P.; Chen, Wei-Chao; Lontchi Jioleo, Jackson; Oliveira, Antonio J. N.; Caha, Ihsan; Francis, Leonard Deepak; Flandre, Denis; Edoff, Marika; Fernandes, Paulo A.; Salome, Pedro M. P.
    Interface recombination in sub-µm optoelectronics has a major detrimental impact on devices’ performance, showing the need for tailored passivation strategies to reach a technological boost. In this work, SiOx passivation based substrates were developed and integrated into ultrathin Cu(In,Ga)Se2 (CIGS) solar cells. This study aims to understand the impact of a passivation strategy, which uses several SiOx layer thicknesses (3, 8, and 25 nm) integrated into high performance substrates (HPS). The experimental study is complemented with 3D Lumerical finite-difference time-domain (FDTD) and 2D Silvaco ATLAS optical and electrical simulations, respectively, to perform a decoupling of optical and electronic gains, allowing for a deep discussion on the impact of the SiOx layer thickness in the CIGS solar cell performance. This study shows that as the passivation layer thickness increases, a rise in parasitic losses is observed. Hence, a balance between beneficial passivation and optical effects with harmful architectural constraints defines a threshold thickness to attain the best solar cell performance. Analyzing their electrical parameters, the 8 nm novel SiOx based substrate achieved a light to power conversion efficiency value of 13.2 %, a 1.3 % absolute improvement over the conventional Mo substrate (without SiOx).
    2022Journal article Open access Show more