Evaluation of Hot Electron Coherent Length Using Well Width Dependence of the Resonance Characteristics of Resonant Tunneling Diodes

In order to evaluate the hot electron coherent length from the resonance characteristics of resonant tunneling diodes (RTDs), the dependence of the resonant level width on various broadening mechanisms is investigated. From the dependence of the resonant level width on the well width, it is shown that the individual contributions to resonant level broadening (phase relaxation and well width variation) can be analyzed separately. The resonant level widths were measured experimentally and compared with theoretical results, and the coherent length was evaluated to range from 80 to 120 nm at 4.2 K in GaInAs at hot electron energies of 50 to 100 meV.