Ternary lead-chalcogenide room-temperature mid-wave infrared detectors grown by spray-deposition

Abstract

Ternary lead chalcogenides, such as PbSxSe1-x, offer the possibility of room-temperature infrared detection with engineered cut-off wavelengths within the important 3-5 micron mid-wave infrared (MWIR) wavelength range. We present growth and characterization of aqueous spray-deposited thin films of PbSSe. Complexing agents in the aqueous medium suppress unwanted homogeneous reactions so that growth occurs only by the heterogeneous reaction on the hydrophilic substrate. The strongly-adherent films are smooth with a mirror-like finish. The films comprise densely packed grains with tens of nm dimensions and a total film thickness of ∼400-500 nm. Measured optical constants reveal absorption out to at least 4.5 μm wavelength and a ∼0.3 eV bandgap intermediate between those of PbS and PbSe. The semiconducting films are p-type with resistivity ∼1 and 85 Ohm-cm at 300 and 80 K, respectively. Sharp x-ray diffraction peaks identify the films as Clausthalite-Galena solid-state solution with a lattice constant that indicates an even mixture of PbS and PbSe. The photoconductive response is observed at both nitrogen and room temperature up to at least 2 kHz chopping frequency.

Spray-on thermoelectric energy harvester

“…PbS film was grown [10] with dissolved NaNO 3 , and Cd(NO 3 ) 2 salts to dope with Na and co-grow CdS inclusions [11]. For NCO film, NaNO 3 , Co(NO 3 ) 2 , and urea were dissolved stoichiometrically in water.…”

“…CdO is the n-type thermoelectric metal oxide material considered here [7][8][9]. The first p-type thermoelectric material we considered was the metal chalcogenide PbS, which we had grown previously for infrared detection [10]. We doped with Na and cogrew CdS nano-inclusions [11].…”

Thermodynamic Analysis and Experimental Study on the Oxidation of PbX (X = S, Se) Nanostructured Layers

“…Lead chalcogenides occupy an important place among semiconductor materials with desired functional properties. Possessing a unique set of electrical properties, they are materials for the manufacture of infrared detectors, chemical sensors, LEDs, solar cells, thermoelectrics, and supercapacitors [1][2][3][4][5][6][7]. It is known that the use of layers based on lead chalcogenides in infrared optoelectronics requires their sensitization by oxidation [8][9][10][11].…”

OPTICAL ATTENUATION MODELLING OF PbSexS1-x QUANTUM DOTS WITH VEGARD'S LAW AND BRUS EQUATION USE

“…Ternary semiconductor such as PbSeS from the group of IV-VI semiconductors are most commonly used in infrared optoelectronics. It offers potential uses for intermediate wavelength detector and produces unique response to cover wavelength ranging from 3000-5000 nm [18]. Hence, this draws wider attention on these materials to design quantum dot solar cells and to improve the conversion efficiency.…”