An In/n-AgGa0.5In0.5Se2/p-Si/Al heterostructure was produced by thermal sequential stacked layer deposition method and the device characteristics were investigated. The compositional analysis showed that the depositions of the intended stoichiometric composition of AgGa0.5In0.5Se2 structure were obtainable by controlling and providing the necessary deposition conditions during the deposition processes. By means of the room temperature Hall effect and transmission measurements, the carrier concentration and optical band gap values were determined as 9 x 10(15) cm(-3) and 1.65 eV, respectively. In addition, temperature- dependent current-voltage (I-V) and the room temperature capacitance-voltage (C-V) measurements of this heterostructure were carried out. The rectification factor was obtained as about 10(4) at 1.20V for all sample temperatures. Depending on the change in the temperature, the series and shunt resistances were calculated as 10(1) and 10(6) Omega, respectively. The studies on the current transport mechanisms showed that there were two different mechanisms at two different voltage regions: tunneling enhanced recombination mechanism in the voltage range of 0.08 and 0.30V and the space charge limited current mechanism in the voltage range of 0.30 and 0.60 V. The barrier height, built-in potential and interface states density of the deposited heterostructure were also calculated and discussed.