High performance infrared photodetectors up to 28 µm wavelength based on lead selenide colloidal quantum dots

Abstract

The strong quantum confinement effect in lead selenide (PbSe) colloidal quantum dots (CQDs) allows to tune the bandgap of the material, covering a large spectral range from mid-to near infrared (NIR). Together with the advantages of low-cost solution processability, flexibility and easy scale-up production in comparison to conventional semiconductors especially in the mid-to near infrared range, PbSe CQDs have been a promising material for infrared optoelectronic applications. In this study, we synthesized monodisperse and high purity PbSe CQDs and then demonstrated the photodetectors working at different wavelengths up to 2.8 µm. Our high quality PbSe CQDs show clear multiple excitonic absorption peaks. PbSe CQD films of different thicknesses were deposited on interdigitated platinum electrodes by a simple drop casting technique to make the infrared photodetectors. At room temperature, the high performances of our PbSe CQD photodetectors were achieved with maximum responsivity, detectivity and external quantum efficiency of 0.96 A/W, 8.13 × 10 9 Jones and 78% at 5V bias. Furthermore, a series of infrared LEDs with a broad wavelength range from 1.5 μm to 3.4 μm was utilized to demonstrate the performance of our fabricated photodetectors with various PbSe CQD film thicknesses.

Solution‐Processed Flexible Broadband Photodetectors with Solution‐Processed Transparent Polymeric Electrode

“…[ 5d,35 ] All these results certainly demonstrate that flexible solution‐processed broadband PDs with a vertical device structure exhibit high R and D * , indicating flexible solution‐processed broadband PDs have great potential applications. [ 36 ]…”

Tin(IV) Methylselenolate as a Low Temperature SnSe Precursor and Conductive “Glue” Between Colloidal Nanocrystals

“…This avoids the introduction of Br − and SCN − ion impurities into the sample (which occur with the tetrabutylammonium bromide and ammonium thiocyanate treatments, respectively) that could potentially be problematic in some scenarios and applications. We anticipate that the PbSe nanocrystal films with SnSe‐like interstitial material in this work could be promising for thin film transistors, and optoelectronics . PbSe is also an excellent thermoelectric material and Sn‐alloyed PbSe can function as topological crystalline insulator …”

“…We anticipate that the PbSe nanocrystal films with SnSe-like interstitial material in this work could be promising for thin film transistors, [42,43] and optoelectronics. [44][45][46][47] PbSe is also an excellent thermoelectric material [48,49] and Sn-alloyed PbSe can function as topological crystalline insulator. [50][51][52]…”

Photoconductive PbSe thin films for infrared imaging

“…The PbSe polycrystalline thin films are widely used for IR detectors, [5][6][7][8][9] IR Photoluminescence, 10 diode laser, 11 up-conversion imaging devices, 12 imaging sensor devices, [13][14][15][16] thermoelectric coolers, 17 and IR solar cells. 3 Recently, the PbSe QD thin films are also being used for IR photodetectors, [18][19][20][21] photovoltaic cells, [22][23][24][25][26][27][28] IR electroluminescent, 29 thermoelectric, 30,31 laser, 32 and field-effect transistor (FET). [33][34][35] Some of the most common applications of IR imaging sensors are night vision, military missile tracking, surveillance systems, search and rescue, research, medical imaging, food production, quality control, industry defect imaging, precision temperature measurement, environmental sensing, meteorology, climatology, and exoplanet exploration.…”