Bifacial thermophotovoltaics: Design and modeling of c-Ge devices

Thermophotovoltaic devices are among the most efficient technologies to convert heat into electricity by means of IR photons emitted from a hot body. Recently, bifacial thermophotovoltaic devices which receive photons on both surfaces have been proposed with potential advantages of higher power dens...

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Detalles Bibliográficos
Autores: Rivera Vila, Gerard|||0009-0003-4206-9102, Gamel, Mansur Mohammed Ali, López Rodríguez, Gema|||0000-0003-4806-5180, López González, Juan Miguel|||0000-0002-5718-5101, Garin Escriva, Moises|||0000-0003-1309-7457, Martín García, Isidro|||0000-0001-8833-9057
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/431763
Acceso en línea:https://hdl.handle.net/2117/431763
https://dx.doi.org/10.1016/j.solmat.2025.113680
Access Level:acceso abierto
Palabra clave:Thermophotovoltaic devices
TPV
Àrees temàtiques de la UPC::Energies::Energia solar tèrmica
Descripción
Sumario:Thermophotovoltaic devices are among the most efficient technologies to convert heat into electricity by means of IR photons emitted from a hot body. Recently, bifacial thermophotovoltaic devices which receive photons on both surfaces have been proposed with potential advantages of higher power density and easier photon recycling. The latter is based on the device transparency to out-of-band photons (Eph < Eg) that can go through it reducing thermal losses on the opposite thermal emitter. In this work, we report on Silvaco ATLAS 3D simulations of bifacial TPV devices based on p-type c-Ge absorbers exploring two substrate resistivities (1.2 and 0.13 O cm). We study the effect of the distance between metal fingers on both surfaces as a critical parameter leading to maximum electrical power densities for ~100 µm. Interestingly, ohmic losses are relaxed by the increase in substrate conductivity due to photogenerated carriers. Bifaciality factor is close to one due to the highly symmetrical design of the device. Finally, we experimentally measure the absorption of out-of-band photons for both substrates. For 1.2 O cm substrates, the absorption is negligible up to ¿ = 10 µm permitting better photon recycling and higher efficiencies up to 21.8 %, compared to 0.13 O cm substrates that lead to 19.6 % despite its reduced ohmic losses.