Enhanced performance of thin-film amorphous silicon solar cells with a top film of 2.85 nm silicon nanoparticles. (February 2016)

• Record Type: Journal Article
• Authors: Chowdhury, Farsad Imtiaz; Alnuaimi, Aaesha; El-Atab, Nazek; Nayfeh, Munir; Nayfeh, Ammar
• Is Part Of: Solar energy. Volume 125(2016)
• Page Start: 332
• Page End: 338
• Publication Date: 2016-02
• Subjects: Nanoparticles -- Photovoltaics -- Photoluminescence -- Charge separation -- Solar cells; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2015.12.030
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Thin film n + -i-p + solar cell with luminescent 2.85 nm Si NPs are fabricated. Improved spectral response; peak IQE increases by 7.62% for Si NPs coated cells. Enhancement is due to down-conversion and charge separation and collection by NPs. Abstract: The performance of thin-film amorphous silicon-based n + -i-p + solar cells in the presence of an exterior top thin film of mono-dispersed ultra-small 2.85 nm diameter silicon nanoparticles has been examined. The silicon nanoparticles have a 530–700 nm red luminescence band with a band peak at 628 nm. Reflectance and the external/internal quantum efficiency (EQE/IQE) of the devices were measured over the range of 300–800 nm. With the Si NPs there is a reduction in reflectivity, which improves the coupling of light to the solar cell. The enhancement in IQE is found to be over the spectral slice 360–610 nm lying between the confinement and the direct band gaps. An enhancement in the IQE in the range of 390–530 nm with a maximum of 31% at 445 nm and a smaller one in the range of 530–610 nm with a maximum of 11% at 590 nm was observed. The increase in the spectral response corresponds to 11.42% increase in short circuit current in agreement with our J – V measurements. The IQE enhancement is explained in terms of two competing channels: excitonic radiative recombination down-conversion in the range 530–610 nm and charge separation and collection in the range 360–530 nm.