Mechanisms of current flow in zinc telluride-zinc selenide heterojunctions

Influence of the base material on the interface properties of ZnO:Al/n-CdS/p-Cd1−xZnxTe heterojunctions

“…In the studied ZnO:Al/CdS/p-CdZnTe heterojunctions, the presence of a high-resistance layer is due to the formation of CdS x Te 1−x solid solution. The formation of the above layer has been detected in the basic region of n-CdS/p-CdTe structures obtained by various methods: high-frequency magnetron sputtering [7], electrodeposition [6], and the method of solid-phase substitution reactions [23]. In [23] has been found that the concentration of equilibrium charge carriers in CdS x Te 1−x is equal to n 0 ≈10 8 cm −3 , in other words this solid solution is high-resistant and is characterized by electronic conductivity.…”

“…The formation of the above layer has been detected in the basic region of n-CdS/p-CdTe structures obtained by various methods: high-frequency magnetron sputtering [7], electrodeposition [6], and the method of solid-phase substitution reactions [23]. In [23] has been found that the concentration of equilibrium charge carriers in CdS x Te 1−x is equal to n 0 ≈10 8 cm −3 , in other words this solid solution is high-resistant and is characterized by electronic conductivity. The inversion of the p-CdZnTe conductivity type at sulfur diffusion and formation of CdS x Te 1−x solid solutions happen due to the formation of sulfur vacancies, which are donors in the CdS x Te 1−x crystal lattice.…”

“…The parameter Γ was estimated using formula (8), using the literature value of the concentration of equilibrium charge carriers in high-resistance CdS x Te 1−x , n 0 =10 8 cm −3 [23], which occurs in the manufacture of n-CdS/p-CdTe heterojunctions. The determined values were: Γ=9330 and Γ=150 for structures made on unannealed and annealed substrates, respectively.…”

High-bias current voltage temperature characteristics of undoped rf magnetron sputter deposited boron carbide (B5C)/p-type crystalline silicon heterojunctions

“…This has been attributed to the existence of high density of extrinsic interface states, formed throughout the fabrication procedure of the junction, and of intrinsic states caused by the lattice mismatch between the junction materials [14][15][16][17][18][19] and/or due to structural imperfections often existing in boron carbide compounds [2,11]. The lowbias current transport in B 5 C/c-Si heterojunctions has been described [3] satisfactorily by a model of the tunnelling of thermally excited carriers through the junction depletion region including tunnelling via impurity-localized states [20][21][22] over a broad temperature range (130-280 K). However, the high-bias behaviour of experimental forward and reverse I-V characteristics of rf-MSD B 5 C/p-type c-Si heterojunctions differs remarkably from that observed at low biases.…”

“…Traditionally, deviations from the expected junction-like forward I-V characteristics encountered at intermediate-and high-bias voltages are attributed to the socalled series-resistance effect, arising from the ohmic voltage drop across highly-resistive materials of the junction under study; so one can then modify the proposed rectifying junction model to include this effect [24][25][26][27][28][29][30]. However, the role of other effects giving rise to the observed deviations in the I-V characteristics of real junctions, such as front/back contacts to the junction, carrier tunnelling through narrow barriers at the hetero-interface regions, inherent bulk conduction in the junction materials, surface effects and high-injection levels, can in many cases be of paramount importance [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Motivated by this diversity in interpreting the observed highbias I-V curves of practical junctions and by the need for more work on the transport properties of rf-MSD B 5 C/c-Si heterojunctions, a detailed investigation of their experimental I-V -T characteristics at high-bias voltages is thus worthwhile.…”