{"title":"BROADBAND PHOTOCURRENT ENHANCEMENT IN LONGWAVE INFRARED QUANTUM DOT PHOTODETECTORS BY SUB-WAVELENGTH SURFACE GRATINGS","authors":"Puminun Vasinajindakaw, Guiru Gu, Xuejun Lu","doi":"10.1142/S1793528813500020","DOIUrl":null,"url":null,"abstract":"We report a sub-wavelength transmission surface grating (TSG) enhanced longwave infrared (LWIR) quantum dot photodetector. Broadband photocurrent enhancement covering the wavelength range from 4 μm to 11 μm is observed. A 4.6 times (4.6×) photocurrent enhancement is obtained at the photodetection wavelength of 8.7 μm. By comparing the simulated diffraction efficiency with the photocurrent enhancement spectrum, we attribute the enhancement to the 1st-order diffraction of the normal infrared (IR) incidence radiation. The photodetectivity (D*) enhancement at different biases is also measured and analyzed.","PeriodicalId":106270,"journal":{"name":"Optics and Photonics Letters","volume":"2 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2013-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Optics and Photonics Letters","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1142/S1793528813500020","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
We report a sub-wavelength transmission surface grating (TSG) enhanced longwave infrared (LWIR) quantum dot photodetector. Broadband photocurrent enhancement covering the wavelength range from 4 μm to 11 μm is observed. A 4.6 times (4.6×) photocurrent enhancement is obtained at the photodetection wavelength of 8.7 μm. By comparing the simulated diffraction efficiency with the photocurrent enhancement spectrum, we attribute the enhancement to the 1st-order diffraction of the normal infrared (IR) incidence radiation. The photodetectivity (D*) enhancement at different biases is also measured and analyzed.