Sandwich-structured Cu2O photodetectors enhanced by localized surface plasmon resonances

Applied Surface Science, Volume 332, 30 March 2015, Pages 340–345.

Ran Jia, Guanjun Lin, Dongfang Zhao, Qian Zhang, Xiaoyu Lin, Naikun Gao, Duo Liu.

State Key Laboratory of Crystal Materials, Shandong University, 27 South Shanda Road, Jinan, Shandong 250100, PR China.

 

Abstract

We report here a facile wet-chemical route to fabricate high performance Cu2O-based plasmonic photodetectors. The Cu2O active layer is sandwiched between Au nanoparticles (Au NPs) and a corrugated Au thin film electrode. We find that the presence of Au NPs will affect the nucleation process of Cu2O thin film on ITO, resulting in different surface morphology, and the localized surface plasmons (LSPs) of Au NPs can greatly increase resonant absorption of the incident light. We show, using I-V and photoresponse measurements, that the sample decorated with Au NPs exhibit greatly improved photo-to-dark current ratio and photoelectric conversion efficiency, with enhancement ratios of 199.7% and 54.3% compared with the sample without Au NPs, respectively. We attribute the observations mainly to optical effects of LSPs, and the effects of the corrugated Au electrode on light reflection are also discussed.

Go To Applied Surface Science

 

Significance Statement

An efficient photodetector must have ideal surface morphology for light trapping and high photoelectric conversion efficiency. We show here that Au nanostructures fabricated on Cu2O can benefit both principles mentioned above. This novel type of photodetector shows not only high photo-to-dark current ratio, but also increased photoelectric conversion efficiency. We attribute the improvements to localized surface plasmon resonances (LSPRs) of Au nanoparticles (Au NPs), which support both light scattering into the Cu2O active layer and enhancement of local electrical field for efficient creation of electron–hole pairs.

 

Figure Legend:

Upper panel: The schematic diagram of light scattering and enhanced electric field due to Au NPs in Cu2O.

Lower panel: The responsivity spectra of the samples with and without Au NPs under laser illumination of five different wavelengths. The maximum enhancement appears at 532 nm, in coincidence with the LSPRs of Au NPs.

Sandwich-structured Cu2O photodetectors enhanced by localized surface plasmon resonances. Advances In Engineering

Check Also

Quantum Leap in QLEDs: Pioneering the Future of Optoelectronics with Smart Material Discovery - Advances in Engineering

Quantum Leap in QLEDs: Pioneering the Future of Optoelectronics with Smart Material Discovery