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RESEARCH PRODUCT
Transient photoresponse and incident power dependence of high-efficiency germanium quantum dot photodetectors
Salvatore CosentinoMaria MiritelloDomenico PacificiIsodiana CrupiSon T. LeAlexander ZaslavskySunghwan LeeDavid C. PaineAntonio TerrasiPei LiuSalvo Mirabellasubject
Materials sciencePhotoresponseReverse biaGeneral Physics and Astronomychemistry.chemical_elementPhotodetectorGermaniumOptical powerPhotoconductionTime-resolvedSettore ING-INF/01 - ElettronicaSeries resistanceOpticsElectrical resistance and conductancePhotodetectorOptical powerEquivalent series resistanceSystematic studybusiness.industryPhotoconductivityInternal quantum efficiencyQuantum-dot photodetectorPhotonWavelengthSemiconductor quantum dots GermaniumchemistryQuantum dotTransient current Electric resistanceOptoelectronicsIncident powerbusinessdescription
We report a systematic study of time-resolved and power-dependent photoresponse in high-efficiency germanium quantum dot photodetectors (Ge-QD PDs), with internal quantum efficiencies greater than 100 over a broad wavelength, reverse bias, and incident power range. Turn-on and turn-off response times (τ on and τ off) are shown to depend on series resistance, bias, optical power, and thickness (W QD) of the Ge-QD layer, with measured τ off values down to ∼40 ns. Two different photoconduction regimes are observed at low and high reverse bias, with a transition around -3 V. A transient current overshoot phenomenon is also observed, which depends on bias and illumination power. © 2012 American Institute of Physics.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-10-15 |