Structural, optical, transient photoconductivity studies and low temperature thermoelectric power measurements on reactively evaporated lead selenide thin films

Photoconductive PbSe thin films for infrared imaging

“…66 Using the potential, Ekuma et al calculated a 1% compression of the lattice parameter for PbSe, resulted in a 0.11 eV bandgap decrease. 66 Streltsov et al showed that with sufficient pressure (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25), PbSe transitions from a cubic (NaCl) semiconductor to an orthorhombic (CsCl) metal and superconductor. 67 Thin films are susceptible to the coefficient of thermal expansion (CTE) mismatch, which can translate to strain.…”

“…The PbSe thin films have unique intrinsic physical properties and band structure, widely used for the NIR and MWIR range applications. 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).…”

“…6 The lead salt narrow bandgap IV-VI semiconductor alloys have provided an exceptional degree of freedom in IR detector design because of their energy bandgap tunability, high optical absorption coefficient, high electron mobility, and low charge carrier thermal generation rate. 1,5,17 The PbSe is a direct bandgap material, which shows a narrow bandgap of around 0.27 eV at room temperature (RT). 5,19 The bulk PbSe semiconductor exhibits some crucial characteristics such as crystal structure of cubic form, large exciton Bohr radius, small effective masses for both electrons and holes, and a large dielectric constant.…”

“…6 The physical properties of the developed PbSe thin films are controlled by different parameters such as the method of deposition, substrate material, substrate temperature, cleanliness of the substrate, rate of deposition, deposition periods, and the background pressure. 17 There is still research going on for PbSe thin film process improvement of existing deposition technology, as well as some new techniques are offered such as photochemical, sonochemical, pulsed laser deposition (PLD), and laser-sintered deposition (LSD). 17 Monocrystalline PbSe photovoltaic detectors are also getting researchers' attention for MWIR and LWIR large format focal plane array (FPA) thermal imaging applications.…”

“…17 There is still research going on for PbSe thin film process improvement of existing deposition technology, as well as some new techniques are offered such as photochemical, sonochemical, pulsed laser deposition (PLD), and laser-sintered deposition (LSD). 17 Monocrystalline PbSe photovoltaic detectors are also getting researchers' attention for MWIR and LWIR large format focal plane array (FPA) thermal imaging applications. 3 With advanced fabrication technology, it is possible to integrate photodetectors with electronic readouts to make detector FPAs, which is now one of the key research focus.…”