In our recent works [1,2], by basing on: (1) the effects of heavy(light) doping and donor (acceptor), d(a), size , which affect the total carrier-minority saturation current density J oI(II) ≡being injected respectively into the heavily doped donor (acceptor)-GaAs emitter-lightly doped acceptor (donor)-Si base regions, HD[d(a)-Si]ER-LD[a(d)-Si]BR, of n + (p + ) − p(n) junction solar cells, respectively, (2) an effective Gaussian donor-density profile to determine J En(p)o , and (3) the use of two experimental points, we investigated the photovoltaic conversion factor n I(II) , short circuit current density J scI(II) , fill factor F I(II) , and finally efficiency η I(II) . Then, the limiting highest efficiencies, 31% (30.65%), were obtained in n + (p + ) − p(n) junction solar cells at 300K.In the present work, by basing on such a treatment method, and using the physical conditions such as: W = 15 μm, N Sb(In) = 10 19 (10 20 ) cm −3 and S = 100 (cm/s ) , according to the highly transparent HD[Sb(In)-GaAs]ER, and then N In(Sb) = 10 18 (10 17 )cm −3 for LD[In(Sb)-