Near-field thermophotovoltaic energy conversion by excitation of magnetic polariton inside nanometric vacuum gaps with nanostructured Drude emitter and backside reflector

Thermophotovoltaic Energy Conversion in Far-to-Near-Field Transition Regime

“…When the vacuum gap becomes comparable to the characteristic wavelength of thermal radiation or narrower, one can observe distinctive thermal radiation originating not only from the evanescent mode (i.e., near-field effect) but also from the propagating mode (i.e., interference effect). , The interference effect begins to appear when the evanescent mode is spectrally suppressed by the PV cell, causing performance fluctuations of the TPV device, as opposed to an overwhelming near-field effect shading the interference effect in the general full spectrum regime. Such phenomena have already been addressed in several theoretical works employing PV cells made of GaSb, − InAs, InSb, and InGaSb ternary alloy semiconductors − since the report by Whale . While fluctuations of power output were observed at the vacuum gap around 1–2 μm between the propagating-mode-dominant far-field regime and the evanescent-mode-dominant near-field regime to some extent in refs and , they mainly emphasized performance improvement due to the near-field effect.…”

Comprehensive analysis of optimized near-field tandem thermophotovoltaic system

“…It is well known that the performance of a TPV system can be enhanced when a gap between the emitter and the TPV cell is smaller than a thermal characteristic wavelength determined by Wien's displacement law [1,[3][4][5][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. In this near-field TPV (NFTPV) system, thermal radiation exceeding the blackbody limitation can be transferred to the TPV cell due to the contribution of evanescent waves.…”

“…Comprehensive analysis of optimized near-field tandem thermophotovoltaic system It was also reported that magnetic polariton (MP) excited by the grating emitter can also tailor the emission spectrum of the NFTPV system [21].…”

“…Alternatively, one can change the configuration of the TPV cell to further improve its performance [11,14,18,19,[21][22][23][24][25][26]. When an infrared reflector is applied to the backside of the TPV cell, the conversion efficiency of the NFTPV system can be significantly increased by reducing the absorption of the sub-bandgap radiation in the TPV cell [11,14,19,21,24]. Recently, it was also found that the non-contact reflector can promote efficient photon recycling [26].…”

“…Recently, it was also found that the non-contact reflector can promote efficient photon recycling [26]. In addition, several groups proposed the thin-film TPV cell confined by a backside reflector and demonstrated the performance enhancement of the NFTPV system through waveguide modes [14], bulk polariton [19], and MP [21]. As an alternative to a p-n junction TPV cell, a metal-semiconductor Schottky junction TPV cell was also employed in the NFTPV system with an advantage of a wider spectral response range compared to the p-n TPV cell [18,22,23].…”