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Wearable Nanogenerators
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Tariq Altalhi, Nanogenerators, 2023
Md Mazbah Uddin, Tanvir Mahady Dip, Suraj Sharma
The mechanism of PSC is dependent mainly on the functionality of the photoactive perovskite layer. The general structure is a sandwich condition where the perovskite layer resides between a couple of charges transporting layers. In the event of getting excited by energy from sunlight, the absorbed electrons in the valence shell of the photoactive layer go up to the conduction layer. There electrons and holes get transported via activities of electron transport layer (ETL) and hole transport layer (HTL), respectively, before they are collected in anode and cathode electrodes (Fu et al. 2018; Hashemi, Ramakrishna, and Aberle 2020). This basic structure can be in any one of the following sequences: ETL-perovskite layer-HTL or HTL-perovskite layer-ETL. Such a PV device facilitates the wearable application as it can be found in solid-state as well as the temperature for production is quite low (Di Giacomo et al. 2016; Roldán-Carmona et al. 2014; Zhang et al. 2016).
Structural and Optical Probe into Rare Earth Doped ZnO for Spectral Conversion in Solar Cells
Published in Odireleng Martin Ntwaeaborwa, Luminescent Nanomaterials, 2022
Francis Otieno, Mildred Airo, Rudolph M. Erasmus, Caren Billing, Alex Quandt, Daniel Wamwangi, David G. Billing
Other previous studies on Eu-doped ZnO include: Pearton et al. [68], who reported green luminescence of the ZnO nanowires with Eu diffusion process observed in the vicinity of 515 nm and attributed it to the thermally activated diffusion of Eu ions. Additionally, the diffusion of Eu in the nanowires due to annealing led to a red-shift of the near band edge (NBE) emission. This chapter examines the relationship between structure and optoelectronic properties of rare earth doped ZnO thin films fabricated by RF magnetron sputtering for photovoltaic applications. As a proof of concept, the films are incorporated in dye sensitized solar cells for two purposes, as an electron transport layer as well as a photoactive layer capable of photon energy management through down shifting effects. In the next section, the methods for fabrication of each RE doped ZnO thin film are presented.
Processing of Nanocomposite Solar Cells in Optical Applications
Published in Kaushik Pal, Hybrid Nanocomposites, 2019
Generally, OSCs are fabricated on a glass substrate with ITO electrodes, as shown in Fig. 10.6. It contains two electrodes that have different work functions. An active layer is packed between these two electrodes. One of the electrodes must absorb the light in the active layer of the cell, so this electrode must be transparent. This electrode is often a conductive oxide that can be a solution processed from a precursor material [50]. The second electrode is a metal. It can easily be evaporated on the active layer. This metal contact reflects off all the light that was not absorbed and thus helps to maximize the exciton generation in the active layer. The choice of electrodes, charge transport layers, and the morphology of the photoactive layer plays a vital role in determining the overall performance of such type of solar cells.
Pyro-phototronic effect enhanced self-powered photodetector
Published in International Journal of Optomechatronics, 2022
Pyro-phototronic effect enhanced photodetectors can be modulated by plasmonic metal nanoparticles (NPs) to obtain tunability of sensitive light waveband. When P-Si/ZnO NWs photodetectors are inserted into a layer of plasmonic Au or Ag NPs between Si and ZnO, spectral insensitivity for the pyroelectric detectors is conquered.[36] The as-fabricated devices decorated with Ag or Au NPs at interface show the best current-response capability at 405 nm or 940 nm respectively. And the wavelength selection ratio is increased by a factor of 80. Response speed of the reported photodetectors can be highly improved through interface modification of plasmonic metal NP. In particular, Si/Ag/ZnO devices display ultrafast rise time of 20 µs under 405 nm light illumination at 825 Hz chopper frequency, whose rise time is 6 times higher than that of the Si/ZnO photodetector. Ultrafast optic-thermal coupling effect induced by LSPR and pyroelectric effect can account for this remarkable enhancement. Plasmonic Au NPs can also be used to enhance UV detection because they can absorb UV light and generate photo-generated electron-hole pairs interband transitions. So, there is a UV photodetector enhanced by pyro-phototronic effect and plasmonic Au NPs. The device architecture has a layered configuration with Au NPs/ZnO/Au film where the sputter-deposited Au NPs and ZnO are photoactive layers. The photoactive layer can display significant absorption of UV light, leading to an increase of photocurrent at 365 nm. Although maximum responsivity and specific detectivity can be obtained as 4.68 A/W and 8.18 × 1011 Jones under a biased condition for the devices, the pyro-phototronic effect from the inherent pyroelectric property of the ZnO contributes to fast photoresponse. The fastest response time is 15 µs without external bias.