Conductivity in heavily doped and compensated epitaxial gallium arsenide layers

Abstract

The dependence of conductivity on electric field and on temperature in heavily doped and strongly compensated liquid-phase epitaxial GaAs layers is investigated. From the dependences on temperature (in low electric fields) and electric field (in strong electric fields) determined experimentally, a localisation radius a and density of states at the Fermi level g&) are determined and the value of the degree of compensation K for 1 -K < 1 is estimated. Good agreement between theory and experiment is obtained.At moderate electric fields qualitative agreement with the existing theoretical models is obtained.

Preparation and properties of heavily doped and strongly compensated Ge films on GaAs

“…Such conductivity has also been observed in amorphous, polycrystalline, and HDSC semiconductors. 10,[52][53][54][55] In various amorphous materials, ͑E͒ in high fields can be described by relationship ͑3͒ with n = 1 2 or 1. [52][53][54][55] Such relationships have been explained in terms of trap-limited conduction such as Poole-Frenkel mechanism and in terms of the space-charge-limited conduction, respectively.…”

“…7 There have been numerous works, both theoretical and experimental, to investigate the influence of electrostatic potential fluctuations, formed by correlated and uncorrelated distributions of impurities, on the electrical and optical properties of various single-crystalline semiconductors. [6][7][8][9][10][11][12][13][14][15][16] However, the problem is quite complex, and there still remain a number of major theoretical and experimental challenges. Besides, there are no sufficiently experimental works on heavily doped semiconductors with very high degree of compensation, in particular, fully compensated.…”

“…This is due to problems for the preparation of strongly and completely compensated semiconductors with high level of doping when Na 3 ӷ 1, where N is the impurity concentration and a is the Bohr radius. Moreover, some experimental studies were performed on wide-bandgap HDSC semiconductors, for example, GaAs, [8][9][10] in which may exist correlation in distribution of impurities. It is well known 6 that the amplitude and spatial size of potential relief in HDSC semiconductors may have a strong dependence on correlation in the impurity distribution, which reduces the potential fluctuations.…”