PHONON-ASSISTED TRAPPING BY SHALLOW IMPURITY IN QUANTUM-WELL

We have considered the capture of electron in a quantum well by shallo w donor impurity due to the interaction with an acoustical phonon. Wav e functions of the nine lowest bound states have been found by variati onal method. We have calculated the rates of transitions between the f ree states and bound states as well as between different bound states. In the case of phonon wavelength much smaller than the width of the w ell L the transition rates are proportional to epsilon-5(n(epsilon) 1/2 +/- 1/2)L-6, where epsilon is the transferred energy, n(epsilon) i s a phonon occupation number.