▁to ▁ox id ize ▁the ▁pass iv ating ▁atom ▁or , ▁E c - E db ▁+ ▁ χ ▁> ▁E I , ▁with ▁the ▁sem icon duct or ▁electron ▁aff inity ▁ χ ▁and ▁atom ▁ion ization ▁energy ▁E I . ▁ ▁Ph on on ▁Sc atter ing ▁ ▁We ▁now ▁consider ▁car rier ▁scatter ing ▁with ▁lattice ▁de form ations ▁term ed ▁ph on ons . ▁Consider ▁the ▁vol um et ric ▁disp lacement ▁such ▁a ▁propag ating ▁wave ▁produces , ▁, ▁which ▁consequ ently ▁results ▁in ▁a ▁time - dependent ▁stra in , ▁ ▁where ▁a ▁simple ▁plane ▁wave ▁is ▁used ▁to ▁describe ▁the ▁ph on on ▁propag ation , ▁. ▁Dis p lacement ▁of ▁atoms ▁away ▁from ▁their ▁equilibrium ▁positions ▁generally ▁causes ▁a ▁change ▁in ▁the ▁electronic ▁band ▁structure ▁( Fig ure ▁ 5 ) ▁where , ▁for ▁scatter ing , ▁we ▁are ▁concerned ▁with ▁electrons ▁in ▁the ▁condu ction ▁band ▁with ▁energy ▁~ EC B , ▁. ▁ ▁The ▁empir ical ▁parameter , ▁Z DP , ▁is ▁term ed ▁the ▁de formation ▁potential ▁and ▁describes ▁electron - phon on ▁coupling ▁strength . ▁Mult ip lying ▁by ▁the ▁ph on on ▁population ▁( B ose – E in stein ▁distribution , ▁N q ) ▁gives ▁the ▁total ▁de formation ▁potential , ▁▁▁ ▁( the ▁reason ▁for ▁the ▁root ▁will ▁be ▁apparent ▁below ). ▁Here , ▁the ▁+ ▁corresponds ▁to ▁ph on on ▁emission ▁and ▁– ▁for ▁ph on on ▁absor ption ▁during ▁the ▁scatter ing ▁event . ▁A ▁note