Complex Investigation of High Efficiency and Reliable Heterojunction Solar Cell Based on an Improved Cu2O Absorber Layer

• Published in: Energies (Basel) Vol. 13; no. 18; p. 4667
• Main Authors: Fara, Laurentiu, Chilibon, Irinela, Nordseth, Ørnulf, Craciunescu, Dan, Savastru, Dan, Vasiliu, Cristina, Baschir, Laurentiu, Fara, Silvian, Kumar, Raj, Monakhov, Edouard, Connolly, James P.
• Format: Journal Article
• Language: English; Norwegian
• Published: Basel MDPI AG 01.09.2020; MDPI
• Subjects: Absorbers; Al:ZnO (AZO); Atomic force microscopy; atomic force microscopy (AFM); Buffer layers; Conduction; Conduction bands; Copper oxides; Correlation analysis; Defects; Efficiency; Experimental research; Fabrication; Failure rates; Heterojunctions; Infrared spectroscopy; Magnetron sputtering; Metal oxides; Morphology; N-doped Cu2O absorber layer; Nitrogen; numerical electro-optical modeling; Optimization; Oxidation; Photovoltaic cells; Physics; Reliability analysis; Scanning electron microscopy; scanning electron microscopy (SEM); Silicon; silicon tandem heterojunction solar cell; Simulation; Solar cells; Spectroellipsometry; Statistical methods; Thin films; X-ray diffraction; Zinc oxide; degradation degree; N-doped Cu 2 O absorber layer; Al:ZnO (AZO); atomic force microscopy (AFM); numerical electro-optical modeling; Fourier-transform infrared (FTIR) spectroscopy; X-ray diffraction (XRD); failure rate; scanning electron microscopy (SEM); silicon tandem heterojunction solar cell; spectroscopic ellipsometry (SE)
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en13184667

This study is aimed at increasing the performance and reliability of silicon-based heterojunction solar cells with advanced methods. This is achieved by a numerical electro-optical modeling and reliability analysis for such solar cells correlated with experimental analysis of the Cu2O absorber layer. It yields the optimization of a silicon tandem heterojunction solar cell based on a ZnO/Cu2O subcell and a c-Si bottom subcell using electro-optical numerical modeling. The buffer layer affinity and mobility together with a low conduction band offset for the heterojunction are discussed, as well as spectral properties of the device model. Experimental research of N-doped Cu2O thin films was dedicated to two main activities: (1) fabrication of specific samples by DC magnetron sputtering and (2) detailed characterization of the analyzed samples. This last investigation was based on advanced techniques: morphological (scanning electron microscopy—SEM and atomic force microscopy—AFM), structural (X-ray diffraction—XRD), and optical (spectroscopic ellipsometry—SE and Fourier-transform infrared spectroscopy—FTIR). This approach qualified the heterojunction solar cell based on cuprous oxide with nitrogen as an attractive candidate for high-performance solar devices. A reliability analysis based on Weibull statistical distribution establishes the degradation degree and failure rate of the studied solar cells under stress and under standard conditions.