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公开(公告)号:GB2508376A
公开(公告)日:2014-06-04
申请号:GB201221502
申请日:2012-11-29
Applicant: IBM
Inventor: GOTSMANN BERND W , KARG FRIEDRICH SIEGFRIED , LOERTSCHER EMANUEL , RIEL HEIKE E , SIGNORELLO GIORGIO
IPC: G01J3/02 , B82Y20/00 , G01J3/12 , H01L31/0352 , H01L31/105
Abstract: An optical spectrometer 1 comprises a photodiode 2 and a straining mechanism 4 for imposing adjustable strain on the photodiode. The spectrometer l includes measurement apparatus 7 for measuring variation of photocurrent with strain at different values of the adjustable strain imposed by the straining mechanism 4. Adjusting the strain allows adjustment of the band gap Eg of the photosensitive region of the photodiode 1, and this determines the cut-off energy for absorption of photons. Measuring variation of photocurrent with strain at different values of the adjustable strain imposed by the straining mechanism allows study of photons within a desired energy range of the band gap energy corresponding to each strain value. The photodiode 2 may comprise a PIN photodiode formed in a nanowire as a radial or axial heterostructure. A polarizer 6 may be adapted to transmit a predetermined polarized component of incident light to the photodiode. The polarizer 6 may comprise a coating on the photodiode.