Band modelling of N-type superlattice detector systems with using empirical pseudopotential method

There are high performance infrared superlattice photodedector structures as nBn(J. B. Rodriguez, 2007) dedectors, M-structured (P. Y. Delaunay, 2009) dedectors, W structured (C. L. Canedy, 2007) dedectors, Complementary barrier infrared detectors (CBIRD) (David Z.-Y. Ting, 2009) , PbIbN (P: p-tipi materyal, N n-tipi materyal, b: bariyer, I: intrinsic [saf, katkısız yarıiletken]) -structured (N. Gautam, 2010) dedectors and N-structred (Ergun & Aydinli, 2012) dedectors taken place in the literature by my Supervisor as a new design. This structure based on a type-II superlattice pin diode is designed for investigating the e-hh wave function overlap functions under reverse bias (U. Kaya, 2013). The structure is called N-structure on the base of real space band profile of 𝐺𝑎𝑆𝑏/𝐴𝑙𝑆𝑏/𝐼𝑛𝐴𝑠 superlattice system. As long as band gap energies of the system has been calculated according to layer thickness correctly with First Principle Method which our team work before (U. Kaya, 2013); pseudo-potentials calculations with plane wave approach have to be done since Bloch functions of the system may not be calculated correctly with First Principle. Especially in 8-12atmospheric window monolayers are more, then, First Principle Calculations take a lot of time and also the absorption and scattering (electron - phonon) processes leads to calculations may not being correctly. For this reason, band calculations are necessary by using Empirical Pseudopotential Method (EPM). In this thesis 𝐼𝑛𝐴𝑠/𝐴𝑙𝑆𝑏/𝐺𝑎𝑆𝑏 type-II superlattice based new detector structure working in the (8-12 µm) atmospheric windows will be designed. Local terms related bulk band structure, band gap and effective mass values will be done in the most accurate way in different temperatures by using EPM.