CaF2 surface passivation of lead selenide grown on BaF2

Responsivity enhancement of mid-infrared PbSe detectors using CaF2 nano-structured antireflective coatings

“…First, the CaF 2 coating could have served as a surface passivation layer, which can effectively prolong the photon generated carrier lifetime, as reported in our previous work. 22 But we did not observe any change in dark current after the CaF 2 coating. Second, the CaF 2 nano-structures could increase incident light lateral scattering and prolong the photon travelling path.…”

“…On the other hand, CaF 2 has very good insulating properties, which makes this material a promising candidate for surface protection and passivation in microelectronics and optoelectronics. 21,22 Therefore, developing a reliable technique to fabricate CaF 2 sub-wavelength nanostructured antireflective coatings could be able to elevate the performance of various optoelectronic devices in mid-infrared wavelength range. In this report, we used room-temperature photoconductive PbSe detectors as an active platform to demonstrate the unique antireflective capabilities of the CaF 2 nanostructured coatings in the mid-IR range.…”

Strain engineering of topological properties in lead‐salt semiconductors

“…ranging from liquid phase epitaxy to molecular beam epitaxy, and several substrates have been used [16][17][18]. Due to their rock-salt structures, lead-salt compounds have (001) natural cleavage planes; alkali-halide MX substrates (M = Na, K and X = Cl, Br, I), having the same structure and comparable lattice constants, have been widely used for IV-VI-compound (001)-oriented epitaxial thin films [16].…”

Lead Selenide Polycrystalline Coatings Sensitized Using Diffusion and Ion Beam Methods for Uncooled Mid-Infrared Photodetection

“…The optical and the optoelectronic characterizations, including PL, optical reflectance, and responsivity spectra, were carried out by the Fourier transform infrared spectroscopy (FTIR), demonstrating that the photoresponsivity was enhanced by the CaF 2 antireflective nanostructured coating to about 200% due to the broadband antireflective effect caused by light bending, as shown in Figure 12a,b. Another effect induced by the CaF 2 nanostructured coating is surface passivation, which could decrease the surface recombination of minority carriers [90,91], as indicated by the PL spectra shown in Figure 12c. These effects and mechanisms were predicted to be responsible for the optoelectronic enhancement of this composite structure.…”