An Investigation of Exciton Binding Energies in Cylindrical Quantum Wires Consist of Various Coaxial Al, As and Ga Alloys under External Electric Fields

Öz

The binding energies of the heavy-hole and light-hole excitons in a cylindrical quantum wires composed of coaxial 𝐴𝑙𝐴𝑠/𝐺𝑎𝐴𝑠/𝐴𝑙𝑥1𝐺𝑎1−𝑥1𝐴𝑠/𝐺𝑎𝐴𝑠/𝐴𝑙𝑥2𝐺𝑎1−𝑥2𝐴𝑠 layers from inside to outside are calculated under the external electric fields. The numerical calculations were carried out by combining 4th order Runge-Kutta method and variational approaches. The exciton binding energies were found as functions of inner GaAs wire thicknesses and the external electric field strengths. The results show that, the exciton binding energies exhibit sharp changes at the certain values of structural parameters and the electric field has significant effects on the binding energies. These properties are thought to be useful technological applications.

Anahtar Kelimeler

• exciton
• quantum wire
• electric field

Eş-eksenli Al, As ve Ga Alaşım Katmanlarından Oluşan Silindirik Kuantum Tellerinde Eksiton Bağlanma Enerjilerinin Dış Elektrik Alanlar Altında İncelenmesi

Öz

İçten dışa eş-eksenli silindirik 𝐴𝑙𝐴𝑠/𝐺𝑎𝐴𝑠/𝐴𝑙𝑥1𝐺𝑎1−𝑥1𝐴𝑠/𝐺𝑎𝐴𝑠/𝐴𝑙𝑥2𝐺𝑎1−𝑥2𝐴𝑠 katmanlarından oluşan bir kuantum telindeki ağır-deşik ve hafif-deşik eksitonlarının bağlanma enerjileri dış elektrik alan etkisi altında elde edilmiştir. Hesaplamalar sayısal olarak 4. Derece Runge-Kutta ve varyasyonel yaklaşım yöntemlerinin birleşimi kullanılarak yapılmıştır. Eksiton bağlanma enerjileri yapıdaki GaAs tel kalınlıklarına ve uygulanan dış elektrik alan şiddetine bağlı olarak bulunmuştur. Sonuçlar eksiton bağlanma enerjilerinin belli yapısal parametre değerlerinde teknolojide kullanışlı olabileceği düşünülen keskin değişimler gösterdiği ve elektrik alanın da bağlanma enerjileri üzerinde önemli etkilere sahip olduğu gözlenmiştir.

Anahtar Kelimeler

• eksiton
• kuantum teli
• elektrik alan

Kaynakça

1. Aktas S, Boz FK, 2008.The binding energy of hydrogenic impurity in multilayered spherical quantum dot. Physica E, 40: 753–758.
2. Aktas S, Boz FK, Bilekkaya A, Okan SE, 2009. The electronic properties of a coaxial square GaAs/AlxGa1_xAs quantum well wire in an electric field. Physica E, 41: 1572–1576.
3. Aktas S, Boz FK, Dalgic SS, 2005. Electric and magnetic field effects on the binding energy of a hydrogenic donor impurity in a coaxial quantum well wire. Physica E, 28: 96–105.
4. Akturk A, Sahin M, Koc F, Erdinc A, 2014. A detailed investigation of electronic and optical properties of the exciton, the biexciton and charged excitons in a multi-shell quantum dot nanocrystal. Journal of Physics D- Applied Physics, 47:28.
5. Boz FK, Aktas S, Bilekkaya A, Okan SE, 2010. The multilayered spherical quantum dot under a magnetic field. Applied Surface Science, 256: 3832–3836.
6. Boz FK, Aktas S, 2005. Magnetic field effect on the binding energy of a hydrogenic impurity in coaxial GaAs/AlxGa1−xAs quantum well wires. Superlattices and Microstructures, 37: 281–291.
7. Boz FK, Aktas S, Bilekkaya A, Okan SE, 2009. Geometric effects on energy states of a hydrogenic impurity in multilayered spherical quantum dot. Applied Surface Science, 255: 6561–6564.
8. Chafaia A, Essaoudi I, Ainanea A, Dujardin F, Ahuja R, 2019. Binding energy of an exciton in a GaN/AlN nanodot: Role of size and external electric field. Physica B: Condensed Matter, 559: 23–28.

9. Galimov AI, Rakhlin MV, Belyaev KG, Klimko GV, Evropeytsevand EA, Toropov AA, 2019. Investigation of the spectrum of exciton excited states in self-organized InAs/AlGaAs quantum dots. Acta Physica Polonica A, (136): 4.
10. Harris R, Terblans J, Swart H, 2015.Exciton binding energy in an infinite potential semiconductor quantum well–wire heterostructure. Superlattices and Microstructures, 86: 456–466.
11. Karki HD, Elagoz S, Baser P, Amca R, Sokmen I, 2007. Barrier height effect on binding energies of shallow hydrogenic impurities in coaxial GaAs/AlxGa1− xAs quantum well wires under a uniform magnetic field. Superlattices and Microstructures, 41 (4), 227-236.
12. Kasapoğlu E, Sari H, Bursal M, Sokmen I, 2003. Exciton absorption in quantum-well wires under the electric field. Physica E, 16: 272 – 243.
13. Kes H, Bilekkaya A, Aktas S, Okan S E, 2017. Binding energy of a hydrogenic impurity in a coaxial quantum wire with an insulator layer. Superlattices and Microstructures, 111: 966-975.
14. Kes H, Okan SE, Aktas S, 2020. The excitons ininfinite potential centered multilayered coaxial quantum wire and the magnetic field effects on their properties, Superlattices and Microstructres, 139: 106421.
15. Kolodka RS, Pundyk IP, Dmitruk I, 2020.Study of Coherent Properties of an Exciton in Semiconductor Quantum Dots. Journal of Nano-and Electronic Physics, 12 (3): 03022.
16. Lopes EM, Cesar DF, Franchello F, Duarte JL, Dias JFL, Laureto E, Elias DC, Pereira MVM, Guimaraes PSS, Quivy AA, 2013. Exciton binding energy in a double quantum well: effect of the barrier shift. Journal of Luminescence, 144: 98–104.
17. Rojas-Briseno JG, Miranda-Pedraza GL, Martinez-Orozco JC, 2017. Exciton binding energy in coupled double zinc blende GaN/InGaN quantum well. Phys. Status Solidi B, 254 (4): 1600461.
18. Saravanan S, Peter AJ, Lee CW, 2015. Combined effects of magnetic and electric fields on the inter band optical transitions in InAs/InP quantum wire. Physica E, 67: 99–104.
19. Wang H, Wang W, Gong Q,Wang S, 2016. External electric field effect on exciton binding energy in InGaAsP/InP cylindrical quantum wires. Physica B, 503:117–120.
20. Wu S, 2011. Exciton binding energy and excitonic absorption spectra in a parabolic quantum wire under transverse electric field. Physica B, 406: 4634–4638.
21. Zhai LX, Wang Y, Liu JJ, 2011. Exciton in an anisotropic parabolic quantum-well wire in the presence of a magnetic field. Journal of Applied Physics, 110: 043701.