Electricity　generation　of　GeSn　single-junction　solar　cell　has　been　carefully　examined　in　both　its　p-on-n　and　n-on-p　configurations　in　its　normal　and　inverted　structures.　The　superior　p(+)/n　construction　with　a　critical　doping　of　the　light-doped　layer　(N-d　=　7.5　x　10(18)　cm(-3))　has　been　observed.　For　the　normal　one,　the　active　layer　should　be　composed　of　50-100　nm　emitter　and　3-5　mu　m　base　to　less　material　costs.　Moreover,　dislocation　density　and　1　MeV　electron　fluence　should　be　lower　than　1　x　10(5)　cm(-2)　and　1　x　10(10)　cm(-2),　respectively,　which　is　helpful　for　obtaining　a　preferable　conversion　efficiency.　To　explore　lower　cost　solar　cell,　the　simulated　results　might　be　favorable　to　guide　experimental　fabrication　of　GeSn　devices.