Spectral absorptance of a metal-semiconductor-metal thin-multilayer structured thermophotovoltaic cell

Abstract

Spectral absorptance of a metal-semiconductor-metal (MSM) thin-multilayer structured thermo-photovoltaic cell was experimentally investigated. A MSM consists of a thin GaSb-semiconductor sandwiched between a top fishnet-type electrode and a flat backside electrode made of gold. A thin GaSb layer was grown on a substrate made of InAs using molecular beam epitaxy, and then all of the InAs substrate was removed using wet etching. The GaSb film was bonded on a surface of gold, which was sputtered on a Si substrate, using a van der Waals bonding method. The top fishnet-type electrode was made using electron beam lithography and a lift-off process. In the case of a 115 nm thick GaSb layer and a square fishnet aperture of a 300 nm × 310 nm size, the spectral absorptance of MSM reached a local peak (95%) at a wavelength of 1.66 µm, which is similar to spectra predicted by numerical simulation. Moreover, the equivalent resonance cavity model and LC circuit model functioned well to indicate the wavelength of several distinct peaks of absorptance.

Radiative energy transfer via surface plasmon polaritons around metal–insulator grating: For better understanding of magnetic polariton

“…There have been numerous studies to manipulate the optical properties of materials using the SPhP and SPP excited by artificially manufactured nano/micrometer-sized structures. Techniques to control spectral transmittance and absorptance help improve the performance of photovoltaic cells (Callahan et al, 2012;Isobe et al, 2020), solar absorber/reflectors (Chirumamilla et al, 2016;Kohiyama et al, 2016;Peoples et al, 2019;Zhang et al, 2022), and radiative coolers (Li et al, 2021;Liu and Takahara, 2017;Rephaeli et al, 2013), among others. The easiest way to excite SPPs is to irradiate obliquely a regularly spaced grating.…”

Resonance modes of a metal-semiconductor-metal multilayer mediated by electric charge

“…The zero-impedance frequencies of nanostructures have been theoretically and experimentally studied. For example, the electromagnetic properties of metal-insulator-metal (MIM) [21,24], metal-dielectric-metal (MDM) [25], and metal-semiconductormetal (MSM) [26,27] multilayers have been studied for over 20 years. Here, the top metal layer can have a rectangular [21,24,28], cross [21,29], or split-ring shape [10,18,30], among others.…”

“…Here, the top metal layer can have a rectangular [21,24,28], cross [21,29], or split-ring shape [10,18,30], among others. Since their significant absorptive and emissive characteristics are useful to improve the efficiency of thermophotovoltaic (TPV) power generation, MSM multilayers using a TPV semiconductor, e.g., gallium antimony (GaSb), were proposed to selectively absorb thermal radiation exceeding the bandgap energy level [26,27]. Moreover, a MIM multilayer used as a frequency-tunable emitter is also a convenient way to provide such a radiation to a TPV cell [4].…”

“…At second, the magnetic response at the resonant frequency is often investigated independently from an electric or a plasmonic response of the nanostructures. Several studies showed a relation between the resonant mode and classical Fabry-Pérot interference, which is an electrical response originated by a propagating wave or SPP [26,27,33]. Wang and Zhang declared that the MP and Fabry-Pérot interference have individual physics and are distinguishable [23].…”

Efficiency Enhancement of Thermophotovoltaic Cells With Different Design Configurations Using Existing Photon Recycling Technologies

“…This technique reduces the interference on the TPV cell which also decreases the temperature reducing the waste heat which is lost in cooling the cell. Furthermore, the use of spectral filters will maintain the temperature of the cell, lesser energy will be utilized for cooling the cells and they also suppress the amount of interference on the surface of the cell by removing lower bandgap photons from the emission spectra and hence achieve better efficiencies than only BSRs (Isobe et al, 2020;Sergeev and Waits, 2020). It also includes the investigation of factors such as EQE, emitter temperature, back surface reflectors, and spectral filters on the efficiency of the TPV cell.…”