Observation of local electroluminescent cooling and identifying the remaining challenges

dc.contributorAalto Universityen
dc.contributor.authorRadevici, Ivanen_US
dc.contributor.authorSadi, Toufiken_US
dc.contributor.authorTripurari, Tripathien_US
dc.contributor.authorTiira, Jonnaen_US
dc.contributor.authorRanta, Sannaen_US
dc.contributor.authorTukiainen, Anttien_US
dc.contributor.authorGuina, Mirceaen_US
dc.contributor.authorOksanen, Janien_US
dc.contributor.departmentDepartment of Neuroscience and Biomedical Engineeringen_US
dc.contributor.departmentTampere Universityen_US
dc.contributor.editorSeletskiy, Denis V.en_US
dc.contributor.editorEpstein, Richard I.en_US
dc.contributor.editorSheik-Bahae, Mansooren_US
dc.description| openaire: EC/H2020/638173/EU//iTPX
dc.description.abstractThe cooling of a light emitting diode (LED) by photons carrying out more energy than was used to electrically bias the device, has been predicted decades ago. 1, 2 While this effect, known as electroluminescent cooling (ELC), may allow e.g. fabricating thermophotonic heat pumps (THP) providing higher efficiencies than the existing solid state coolers, 3 ELC at powers sufficient for practical applications is still not demonstrated. To study high-power ELC we use double diode structures (DDSs), which consist of a double heterojunction (DHJ) LED and a photodiode (PD) grown within a single technological process and, thus, enclosed in a cavity with a homogeneous refractive index. 4, 5 The presence of the PD in the structure allows to more directly probe the efficiency of the LED, without the need for light extraction from the system, reducing undesirable losses. Our analysis of experimentally measured I - V curves for both the LED and the PD suggests that the local efficiency of the high-performance LEDs we have fabricated is approximately 110%, exceeding unity over a wide range of injection current densities of up to about 100A/cm 2 . At present the efficiency of the full DDS, however, still falls short of unity, not allowing direct evidence of the extraction of thermal energy from the LED. Here we review our previous studies of DDS for high-power EL cooling and discuss in more detail the remaining bottlenecks for demonstrating high-power ELC in the DDS context: the LED surface states, resistive and photodetection losses. In particular we report our first surface passivationmeasurements. Further optimization therefore mainly involves reducing the influence of the surface states, e.g. using more efficient surface passivation techniques and optimizing the PD. This combined with the optimization of the DDS layer thicknesses and contact metallization schemes is expected to finally allow purely experimental observation of high-power ELC.en
dc.description.versionPeer revieweden
dc.identifier.citationRadevici , I , Sadi , T , Tripurari , T , Tiira , J , Ranta , S , Tukiainen , A , Guina , M & Oksanen , J 2019 , Observation of local electroluminescent cooling and identifying the remaining challenges . in D V Seletskiy , R I Epstein & M Sheik-Bahae (eds) , Photonic Heat Engines : Science and Applications . , 109360A , Proceedings of SPIE , vol. 10936 , SPIE , Photonic Heat Engines: Science and Applications , San Francisco , California , United States , 03/02/2019 . https://doi.org/10.1117/12.2505814en
dc.identifier.otherPURE UUID: 9723ec85-f213-4d93-b0a2-991ff6fc2572en_US
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/9723ec85-f213-4d93-b0a2-991ff6fc2572en_US
dc.identifier.otherPURE LINK: http://www.scopus.com/inward/record.url?scp=85065604697&partnerID=8YFLogxKen_US
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/35183142/109360A.pdfen_US
dc.relation.ispartofPhotonic Heat Engines: Science and Applicationsen
dc.relation.ispartofseriesPhotonic Heat Enginesen
dc.relation.ispartofseriesProceedings of SPIEen
dc.relation.ispartofseriesVolume 10936en
dc.subject.keywordDouble diode structuresen_US
dc.subject.keywordElectroluminescent coolingen_US
dc.subject.keywordIII-V semiconductorsen_US
dc.subject.keywordQuantum efficiencyen_US
dc.subject.keywordSurface statesen_US
dc.titleObservation of local electroluminescent cooling and identifying the remaining challengesen
dc.typeConference article in proceedingsfi