HgTe colloidal quantum dot photodiodes for extended short-wave infrared detection

Abstract

HgTe colloidal quantum dots are investigated as the active material in photodiodes for extended short-wave infrared up to 2.6 μm. The HgTe colloidal quantum dots photodiodes achieve external quantum efficiencies above 50% and specific detectivities of 1 × 1011 at 2.2 μm at room temperature with a microsecond response time and compete with commercial extended InGaAs photodiodes.

Infrared photoconduction at the diffusion length limit in HgTe nanocrystal arrays

“…The obtained specific detectivity value competes with the best HgTe NC-based diode structure 38 operated in the short-wave IR, see Fig. 3b .…”

“…For the sake of comparison with state of the art diode we also provide the performance of the photodiode from ref. 38 . c Specific detectivity measured at 200 K as a function of the electrode spacing.…”

Advances of Sensitive Infrared Detectors with HgTe Colloidal Quantum Dots

“…Over the past decade, CQDs have been widely used in a variety of applications, including solar cells [24], spectrometers [25], phototransistors [26], FPA imagers [27], lasers [28], LEDs [29]. Among all the CQDs systems, mercury telluride (HgTe) CQDs have demonstrated the highest infrared spectral absorption tunability covering main important atmospheric windows including short-wave infrared (SWIR, 1.5-2.5 µm) [30][31][32][33], mid-wave infrared (MWIR, 3-5 µm) [34][35][36][37][38][39][40][41][42], long-wave infrared (LWIR, 8-12 µm) [43,44] and even the terahertz (THz) [45,46], appearing as promising candidates to substitute conventional semiconductors to achieve good detection performance with low cost. This review will be described from the following aspects, including: synthesis of infrared CQDs, infrared CQDs photodetectors, multispectral CQDs photodetectors and CQDs FPA.…”

Bringing Colloidal Quantum Dots to Detector Technologies

“…Thus, two small companies-Episensors and QDIR-are working independently to commercialize HgTe CQD photodetector arrays for IR imaging. HgTe CQD-based photoconductors, 10 phototransistors, 11 and photodiodes 12,13 have been reported, showing figures-of-merit rapidly approaching commercial semiconductor alloys' levels. EQE often is lower for CQD detectors than for bulk detectors, the D* of CQDs quickly is approaching bulk detector performances.…”

“…Unless otherwise specified, the data presented are for a detector operating at room temperature. Green circle = HgTe CQD photodiodes; 12 , 13 green triangle = phototransistors; 11 green square = photoconductors; 10 blue circle = PbS CQD photodiodes; 8 blue triangle = phototransistors; 7 blue square = photoconductors; 6 red circle = HgCdTe photodiodes; 14 , 15 orange circle = InGaAs photodiodes; 16 , 17 and yellow circle = InSb photodiodes 18…”