We have demonstrated an 820 nm cutoff CdTe nBn photodetector with ZnTe barrier layer grown on an InSb substrate. At room temperature, under a bias of -0.1 V, the photodetector shows Johnson and shot noise limited specific detectivity (D∗) of 3 × 1013 cm Hz1/2/W at a wavelength of 800 nm and 2 × 1012 cm Hz1/2/W at 200 nm. The D∗ is optimized by using a top contact design of ITO/undoped-CdTe. This device not only possesses nBn advantageous characteristics, such as generation-recombination dark current suppression and voltage-bias-addressed two-color photodetection, but also offers features including responsivity enhancements by deep-depletion and by using a heterostructure ZnTe barrier layer. In addition, this device provides a platform to study nBn device physics at room temperature, which will help us to understand more sophisticated properties of infrared nBn photodetectors that may possess a large band-to-band tunneling current at a high voltage bias, because this current is greatly suppressed in the large-bandgap CdTe nBn photodetector.

Original languageEnglish (US)
Article number121112
JournalApplied Physics Letters
Issue number12
StatePublished - Sep 19 2016


ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

He, Z. Y., Campbell, C. M., Lassise, M. B., Lin, Z. Y., Becker, J. J., Zhao, Y., Boccard, M., Holman, Z., & Zhang, Y-H. (2016). CdTe nBn photodetectors with ZnTe barrier layer grown on InSb substrates. Applied Physics Letters, 109(12), [121112]. https://doi.org/10.1063/1.4963135