Bandgap-Engineered pSi/n-CdₓS₁₋ₓ Heterojunctions: Effect of Composition on Optoelectronic Behavior
Abstract
This study provides a comprehensive analysis of the electrophysical properties of the pSi/n-CdₓS₁₋ₓ heterojunction, where the cadmium composition x varies continuously from 0 to 1. The investigation integrates theoretical modeling, numerical simulations, and experimental validation employing typical doping concentrations of p = 2 × 10¹⁷ cm⁻³ for p-type porous silicon and n = 1 × 10¹⁸ cm⁻³ for n-type CdₓS₁₋ₓ. Particular attention is devoted to the temperature-dependent evolution of key material parameters, including the bandgap energy Eg(T), intrinsic carrier concentration nᵢ(T), and the Debye temperature Θ(x). As the cadmium fraction increases, the bandgap narrowing in CdₓS₁₋ₓ becomes evident, while porous silicon maintains a relatively wide and thermally stable Eg(T), resulting in a substantial band offset (ΔEg) that enhances charge carrier separation across the interface. Furthermore, the reduction of Θ(x) with increasing cadmium concentration modulates phonon scattering and recombination dynamics, thereby influencing charge transport characteristics. The analysis of current transport mechanisms indicates that the junction behavior is predominantly controlled by temperature- and composition-dependent band alignment and carrier recombination processes. The obtained results validate the proposed physical model and demonstrate the promising potential of pSi/n-CdₓS₁₋ₓ heterostructures for high-temperature and acoustically tunable optoelectronic devices.
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References
W. Duncan, and A.R. Smellie, “Si–CdS heterojunction memory diodes,” J. Appl. Phys. 49(8), 4098–4104 (1978). https://doi.org/10.1063/1.325371
N.D. Akhavan, I. Ferain, P. Razavi, R. Yu, and J.-P. Colinge, “Junctionless multigate transistors : fabrication and performance,” Appl. Phys. Lett. 98(10), 103510 (2011). https://doi.org/10.1063/1.3559625
A.V. Babichev, H. Zhang, P. Lavenus, F.H. Julien, A.Y. Egorov, Y.T. Lin, and M. Tchernycheva, “Nanowire heterojunction optoelectronics,” Appl. Phys. Lett. 103(20), 201103 (2013). https://doi.org/10.1063/1.4829756
B. Pal, K.J. Sarkar, and P. Banerji, “Optical and electronic properties of nanostructured solar cells,” Sol. Energy Mater. Sol. Cells 204, 110217 (2020). https://doi.org/10.1016/j.solmat.2019.110217
I. Aberg, G. Vescovi, D. Asoli, U. Naseem, J.P. Gilboy, C. Sundvall, and L. Samuelson, “III–V nanowire photovoltaics on silicon,” IEEE J. Photovoltaics, 6(1), 185–190 (2016). https://doi.org/10.1109/JPHOTOV.2015.2484967
P. Dubey, B. Kaushik, and E. Simoen, “Analytical modeling of advanced nano-CMOS devices,” IET Circuits Devices Syst. (2019). https://doi.org/10.1049/iet-cds.2018.5169.
A.M. de Souza, D.R. Celino, R. Ragi, and M.A. Romero, “Emerging devices modeling,” Microelectron. J. 119, 105324 (2021). https://doi.org/10.1016/j.mejo.2021.105324
D.B. Istamov, O.A. Abdulkhayev, and Sh.M. Kuliyev, “Limiting characteristics of silicon diode temperature sensors for determining the maximum temperature with specified measurement accuracy,” UNEC J. Eng. Appl. Sci. 5(1), 63-69 (2025). https://doi.org/10.61640/ujeas.2025.0507
D.B. Istamov, O.A. Abdulkhayev, Sh.M. Kuliyev, N. Abdullayev, A.Sh. Ashirov, and D.M. Yodgorova, “Temperature response curve of silicon diode temperature sensors,” East Eur. J. Phys. (2), 287-291 (2025). https://doi.org/10.26565/2312-4334-2025-2-35
R. Seoudi, A.A. Shabaka, M. Kamal, E.M. Abdelrazek, and W. Eisa, “Size-dependent CdS nanoparticle characteristics,” Physica E, 45, 47–55 (2012). https://doi.org/10.1016/j.physe.2012.07.006
J.Sh. Abdullayev, and I.B. Sapaev, “Optimization of temperature effects in radial p–n junctions,” East Eur. J. Phys. (3), 344–349 (2024). https://doi.org/10.26565/2312-4334-2024-3-39
J.Sh. Abdullayev, and I.B. Sapaev, “Temperature and doping optimization in p–n and p–i–n devices,” Eurasian Phys. Tech. J. 21(3), 21–28 (2024). https://doi.org/10.31489/2024No3/21-28
J.Sh. Abdullayev, “Effect of linear doping on p–n junction properties,” East Eur. J. Phys. (1), 245–249 (2025). https://doi.org/10.26565/2312-4334-2025-1-26
R.D. Trevisoli, R.T. Doria, M. de Souza, S. Das, I. Ferain, and M.A. Pavanello, “Repetition,” IEEE Trans. Electron Devices, 59(12), 3510 (2012). https://doi.org/10.1109/TED.2012.2219055
J.Sh. Abdullayev, and I.B. Sapaev, “Ideality factor variation at cryogenic temperatures,” East Eur. J. Phys. (4), 329–333 (2024). https://doi.org/10.26565/2312-4334-2024-4-37
A.V. Babichev, H. Zhang, P. Lavenus, F.H. Julien, A.Y. Egorov, Y.T. Lin, and M. Tchernycheva, “GaN nanowire ultraviolet photodetector with a graphene transparent contact,” Appl. Phys. Lett. 103(20), 201103 (2013). https://doi.org/10.1063/1.4829756
J.Sh. Abdullayev, I.B. Sapaev, and Kh.N. Juraev, “Incomplete ionization analysis in radial p–n junctions,” Low Temp. Phys. 51, 60–64 (2025). https://doi.org/10.1063/10.0034646
J.Sh. Abdullayev, and I.B. Sapaev, “GaAs/Si heterojunction analysis,” East Eur. J. Phys. (1), 204–210 (2025). https://doi.org/10.26565/2312-4334-2025-1-21
R. Bebitov, O. Abdulkhaev, D. Yodgorova, D. Istamov, G. Khamdamov, Sh. Kuliyev, J.Sh. Abdullaev, et al., “Potential distribution over temperature sensors of p-n junction diodes with arbitrary doping of the base region,” E3S Web Conf. 401, 03062 (2023). https://doi.org/10.1051/e3sconf/202340103062
R.R. Bebitov, O.A. Abdulkhaev, D.M. Yodgorova, D.B. Istamov, G.M. Hamdamov, Sh.M. Kuliyev, A.A. Khakimov, and A.Z. Rakhmatov, “Dependence of the accuracy of the silicon diode temperature sensors for cryogenic thermometry on the spread of their parameters,” Journal "Low Temperature Physics, 49(2), 277–282 (2023). https://doi:10.1063/10.0016843
R.R. Bebitov, O.A. Abdulkhaev, D.M. Yodgorova, D.B. Istamov, Sh.M. Kuliyev, A.A. Khakimov, A.B. Bobonazarov, et al, “Distribution of impurities in base-depleted region of diode temperature sensor,” Low Temperature Physics, 50(5), 418–424 (2024). https://doi:https://doi.org/10.1063/10.0025635
J.Sh. Abdullayev, and I.B. Sapaev, “Modeling Si and GaAs junctions,” Phys. Sci. Technol. 11(3–4), 39–48 (2024). https://doi.org/10.26577/phst2024v11i2b05
O. Toqtarbayuly, M. Baysariev, A. Qaysha, et al., “Enhancing dye-sensitized solar cell efficiency using gas-phase CVD GaN,” Eurasian Phys. Tech. J. 21(4), 131–139 (2024). https://doi.org/10.31489/2024No4/131-139
I. Sapaev, I.B. Sapaev, et al., “Conference paper on p–n junction features,” E3S Web Conf. 383, 04022 (2023). https://doi.org/10.1051/e3sconf/202338304022
J.Sh. Abdullayev, I. Sapaev, N. Esanmuradova, S. Kadirov, and S. Kuliyev, “Temperature and concentration in radial p–n junctions,” East Eur. J. Phys. (2), 220–225 (2025). https://doi.org/10.26565/2312-4334-2025-2-24
J.Sh. Abdullayev, I.B. Sapaev, and S.R. Kadirov, “Recombination's effect on radial p–n junction efficiency,” East Eur. J. Phys. (2), 252–257 (2025). https://doi.org/10.26565/2312-4334-2025-2-30
N.V. Deshmukh, T.M. Bhave, A.S. Ethiraj, et al., “PL and I–V characteristics of CdS-nanoparticles/porous-Si,” Nanotechnology 12(3), 290–294 (2001). https://doi.org/10.1088/0957-4484/12/3/316
R. Zellagui, H. Dehdouh, M. Adnane, M.S. Akhtar, and M.A. Saeed, “CBD deposition of CdₓZn₁₋ₓS thin films,” Optik, 164, 164377 (2020). https://doi.org/10.1016/j.ijleo.2020.164377
N.A. Shah, A. Ali, S. Hussain, A. Maqsood, “CdCl₂-treated CdTe films via sublimation,” J. Coatings Technol. Res. 7(1), 105–110 (2008). https://doi.org/10.1007/s11998-008-9146-0
J.Sh. Abdullayev, L. Abdullayeva, L. Agamalieva, and R. Ismailova, “Correlating Ni microstructure with Schottky barrier homogeneity in monolayer MoS₂ field-effect transistors,” Advanced Physical Research, 7(3), 350–357 (2025). https://doi.org/10.62476/apr.73350
O.O. Akinwunmi, G.O. Egharevba, and E.O.B. Ajayi, “CdS, ZnS, CdZnS nanoparticles embedded in polystyrene,” J. Modern Phys. 5(5), 416–423 (2014). https://doi.org/10.4236/jmp.2014.55036
C.-F. Wang, B. Hu, H.-H. Yi, and W.-B. Li, “Optoelectronic characterization of ZnS/silicon systems,” Chin. Opt. Lett. 7(6), 481 484 (2009). https://doi.org/10.3788/COL20090705.0432
J.Sh. Abdullayev, I.B. Sapaev, J.Sh. Abdullayev, D.A. Juraev, M.J. Jalalov, and E.E. Elsayed, “Mathematical Modeling of Incomplete Ionization in Radial p-Si/n-GaAs Heterojunctions: Temperature and Doping Effects,” Journal of Electronic Materials, 54, 1–9 (2025). https://doi.org/10.1007/s11664-025-12391-8
A. Laouid, A.A. Belghiti, K. Wisniewski, et al., “Mn/Ca-doped ZnS thin films: morphology and PL,” Mater. Chem. Phys. 290, 127870 (2024). https://doi.org/10.1016/j.matchemphys.2024.129270
J. Xiang, H. Wang, X. Wang, X. Chen, T. Wu, H. Wan, Y. Liu, and H. Wang, “CdₓZn₁₋ₓS nanocrystals for visible-light photocatalysis,” RSC Adv. 9(7), 4001–4007 (2019). https://doi.org/10.1039/C8RA09408J
M. Wang, A. Debernardi, Y. Berencén, R. Heller, C. Xu, Y. Yuan, et al., “Breaking doping limit in silicon via deep impurities,” Phys. Rev. Appl. 11(5), 054039 (2019). https://doi.org/10.1103/PhysRevApplied.11.054039
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