Performance Comparison of X- and <inline-formula> <tex-math notation="LaTeX">$\gamma$ </tex-math> </inline-formula>-Ray CdTe Detectors With MoO_{<italic>x</italic>}, TiO_{<italic>x</italic>}, and TiN Schottky Contacts

Graphene/semi-insulating single crystal CdTe Schottky-type heterojunction X- and γ-Ray Radiation Detectors

“…However, the signal from 137 Cs isotope (662 keV) is measured with a very promising resolution of 6.1% at the same reverse bias (see Fig. 5b) that is slightly better in comparison to a conventional In/CdTe/Pt detector, measured at the same temperature of 300 K 23 .

Figure 5Spectra of 241 Am (59 keV) ( a ) and 137 Cs (662 keV) ( b ) X-ray sources taken with the graphene/CdTe/Au detector at 300 K.

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CdTe X/γ-ray Detectors with Different Contact Materials

“…Moreover, MoO x is favorably distinguished by its high transparency for visible radiation and relatively low specific electrical resistivity. Due to these properties and high work function (5.2-6 eV) [37], MoO x has been considered and studied as a promising candidate to form efficient electrical contacts to semi-insulating p-CdTe semiconductor crystals [21][22][23][24][25].…”

“…An additional confirmation of this assumption is provided by the comparison of the experimental I-V characteristics with the calculation results obtained in the framework of the Sah-Noyce-Shockley theory of generation-recombination of carriers, adapted to a metal-semiconductor (Schottky) contact (Figure 5). According to the theory [41], the generation current I g can be found by integration of the generation rate U(x) throughout the entire SCR as shown in [17,[21][22][23][24][25][42][43][44][45][46]:…”

“…During the last two decades, we have widely used semi-insulating CdTe semiconductors, produced by Acrorad for material characterization [15][16][17] and elaboration of both Schottky diode-type [18][19][20][21][22][23][24][25][26][27] and M-p-n structured [27][28][29][30][31][32][33][34] X/γ-ray detectors. Using different metals (Ni, Cr, In, Al, and Au) for electrodes to form appropriate Schottky and ohmic electrical contacts or employing laser-induced doping of a thin CdTe layer with In, we have obtained high performance diode-type X/γ-ray detectors with excellent roomtemperature energy resolution.…”

“…We have recently studied other electrode materials (graphene, metal oxides and nitrides) different from metals used before and developed the techniques to employ them for the formation of Schottky and ohmic electrical contacts to Acrorad's semi-insulating CdTe crystals [21][22][23][24][25][26]. We have interested to develop this trend, in particular using molybdenum oxide as a promising material for ohmic contact formation [35][36][37][38][39][40].…”