Determination of band tail widths in MOCVD grown InGaN single layer within GaN based p-i-n LED structure through photo-induced measurements

Orhan Özdemir (1) , Kutsal Bozkurt (1) , Neslihan Ayarcı Kuruoğlu (1) , Hanife Baş (1) , Fahrettin Sarcan (2) , Ayşe Erol (2) , Bandar Alshehri , Karim Dogheche (3, 4) , El Hadj Dogheche (3, 4)

1 YTU - Yildiz Technical University
2 Istanbul University
3 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
4 UPHF - Université Polytechnique Hauts-de-France

Within a p-i-n LED structure, energy band gaps of MOCVD grown %10 In content InGaN and GaN layers were obtained through traditional UV–Visible transmission-absorption measurements and utilizing surface photovoltage (SPV) and spectral photoconductivity (SPC) measurements. Moreover, all applied techniques determined that the total band offset between InGaN and GaN layers were around 0.3–0.4 eV. Furthermore, the temperature dependence of band gaps of each InGaN and GaN layer was analyzed through a modified Varshni relation where both Varshni coefficients and band tail energy width were explored. Band tails in a modified Varshni relation, SPV and SPC measurements were in agreement with each other and originated Franz-Keldysh Effect attributed to the presence of photon assisted tunneling.

Mots clés: Franz-Keldysh effect; InGaN layer; Spectral photo-conductivity; Surface photo-voltage

Domaines: Sciences de l'ingénieur [physics]

Orhan Özdemir, Kutsal Bozkurt, Neslihan Ayarcı Kuruoğlu, Hanife Baş, Fahrettin Sarcan, et al.. Determination of band tail widths in MOCVD grown InGaN single layer within GaN based p-i-n LED structure through photo-induced measurements. Journal of Luminescence, 2023, 255, pp.119543. ⟨10.1016/j.jlumin.2022.119543⟩. ⟨hal-03918270⟩