Transport properties of electrons in energy band tails

摘要: Abstract Transport properties of electrons in energy band tails disordered semiconductors are studied experimentally using a material system which (i) the width and shape band-tail approximately known (ii) Fermi is controllable. The heavily-doped, closely-compensated, crystalline n-GaAs whose compensation ratio can be made arbitrarily close to unity by use two techniques that described detail. This control level through permits measurement transport at various energies band-tail. Using having ∼50 meV, measurements have been temperature dependence d.c. conductivity Hall coefficient, frequency a.c. electric field (the last low temperatures). evidence demonstrates progressively greater localization states deeper tails. No sign found of...