Electronic Structure of Semiconductor Nanocrystals.pdf

第 27 卷 　第 2 期 2006 年 2 月 半 　导 　体 　学 　报 C HIN ES E J OU RNAL O F S EMICOND U C TO RS V ol . 27 　N o. 2 Feb. ,2006 3 Project supp orted by t he U . S. DO E (Nos . D E2A C36299 GO10337 a nd D E2A C03276S F0098)- Corresp onding aut hor . Email :J i ngbo_Li @nrel . gov 　Received 22 October 2005 ν 2006 Chinese Institute of Elect ronics Electronic Structure of Semiconductor Nanocrystals 3 L i J ingbo 1 ,- , Wa ng L inwa ng 2 , a nd Wei Suhuai 1 (1 National Renewable Energy L aboratory , Golden , CO 　80401 , USA) (2 L awrence Berkeley National L aborat ory , Berkeley , CA 　94720 , USA) Abstract : This p aper reviews our recent develop ment of t he use of t he large2scale pseudop otential met hod t o cal2 culate t he elect ronic st ructure of semiconduct or nanocrystals ,such as quantum dots and wires ,which of ten contain tens of t housands of at oms . The calculated size2dep endent excit on energies and absorp tion sp ect ra of quantum dots and wires are in good agreement wit h exp eriments . We show t hat t he elect ronic st ructure of a nanocrystal can be tuned not only by its size , but also by its shape . Finally ,we show t hat def ect p roperties in quantum dots can be sig2 nif icantly diff e rent f rom t hose in bulk semiconduct ors . Key words : elect ronic st ructure ; semiconduct or ; nanocrystals EEACC : 2520 CLC number : TN304 　　　Document code : A 　　　Article ID : 025324177 (2006) 0220191206 1 　Introduction D uri ng t he last deca de , se miconduct or na no2 crystals such as qua nt um dots (Q Ds) a nd qua nt um wires (Q Ws) [ 1 ] have at t racted much at te ntion be2 cause t he p hysical p rop e rties of t he na nocrystals such as t he ba nd gap a nd op tical t ra nsitions ca n be tailore d conti nuously by size or shap e . This f ea2 t ure op e ns up grea t p ote ntial f or novel device ap2 p lications f rom lase rs t o sola r cells t o si ngle2elec2 t ron t ra nsist ors [ 2～4 ] . Ma ny of t hese app lications requi re knowle dge of t he size2 a nd shap e2dep e