Super thin Schottky solar cell structure with a back isotope heterojunction

Thin monocrystalline GaAs films can be used for a solar cells applications as cheap and effective convectors of solar energy. One amount of methods of such films obtaining is Free Film Technology (FFT). This method permits to form the monocrystalline Ga(Al)As film separated from an initial substrate with a thin metallic layer having a low melting temperature. Such process actualize in the Sn Ga al As [GaAs system at the fixed conditions. In this study Au[n-GaAs [n-AlGaAs thin film solar cell structure was examined. The main structure was creation in LPE process with one melt only containing Sn + Ga(10 at . % ) + Al (.15 - .20 at . %) components. The growth was carried out with cooling rate of 3K [min in range from 1000K to room temperature on (100) GaAs substrates. As a results of the process sand which type structure (it was the metallic layer were in range 5-7 um and 5-10 um respectively. A requisite distribution of AlAs into Ga(Al)As film was primarily estimated and than was measured with X-ray microanalysis method. Au-coating was deposited by electron beam evaporation on obtained samples. After the Schottky barrier device was formed barrier height C-V and I-V performance and photoelectric properties were measured. On the thin film structures were obtained V/sub oc/ = 73. - .75 V and conversion efficiency at AM 1.5 = 10.1%. It was shown that parameters of the barrier solar cell depend on existence of electron concentration gradient at frontal surface and back isotope heterojunction. Band diagram of the thin film barrier structure is adduced. (author)