Formation of diode detectors by nanosecond laser irradiation of CdTe-In interface from the semiconductor side

Effects of Heating on Electrical and Spectral Properties of In/CdTe/Au X- and γ-ray Detectors with a Schottky Barrier or Laser-induced p–n Junction

“…Metal-CdTe Schottky diodes have been generally fabricated and used as X-and γ-ray detectors. (2)(3)(4)(5)9,12,20,21) On the other hand, In/CdTe/Au barrier structures formed by frontside (5)(6)(7) or backside laser irradiation (16)(17)(18)(19) have been considered as p-n junction diodes, which have also shown high detection efficiency. Figure 2 shows the schematic of the structures of In/CdTe/Au X-and γ-ray detectors formed as (a) a Schottky diode (without laser irradiation) and (b) a p-n-junction diode by backside laser irradiation.…”

“…A p-n junction was created in the CdTe subsurface layer by laser-induced backside doping with In atoms from the deposited In electrode, which served as the dopant source. (16)(17)(18)(19) A schematic of the experimental setup for the laser-induced doping procedure is shown in Fig. 1.…”

“…The optimal conditions for laser-induced backside doping were studied and estimated in our earlier publications. (16)(17)(18)(19) The selected laser energy in the experiments was E = 11 mJ for which the temperature of the In surface at the In/CdTe interface increased up to near the In melting point. The number of laser pulses, used for backside doping, was 30.…”

Modeling of diffusion motion of In nanoparticles in a CdTe crystal during laser-induced doping

“…The p-type CdTe crystal used in this experiment is doped with Cl element, and the resistivity is (> 10 9 Ω•сm). CdTe has a very high light absorption coefficient (> 5×10 5 /cm). A CdTe film with a thickness of only 2 μm has an optical absorption coefficient of more than 90% under standard conditions AM 1.5, and the highest theoretical conversion efficiency reaches 28 % [4].…”

“…Laser processing of CdTe has been successfully used to modify the structure and properties of surface nano-layers and change different characteristics of the semiconductor. Of particular interest is application the laser assisted doping technique to suppress the dopant self-compensation mechanism, and reach introducing and efficient electrical activation of In atoms in CdTe [5][6][7][8][9][10]. We have continued development and optimization the methods of chemical surface processing of CdTe crystals, laser induced doping technique for creation of a built-in p-n junction by nanosecond laser irradiation of the CdTe crystals precoated with a relatively thick In film which serves both as an n-type dopant source and electrical contact (electrode) after the doping and deposition of the second electrode [7][8][9][10].The formation of a surface nano-layer highly-doped with In in semi-insulating detector-grade p-like CdTe crystals and creation of In/CdTe/Au diodes with a shallow and sharp p-n junction has been studied and mechanism of laser-induced doping is analyzed.…”