Electrical and photoelectric properties of Yb/CIGS thin film Schottky photodiode

[Display omitted] •Yb rare earth metal was first used for Schottky metallization on CIGS.•The value of zero bias barrier height is remarkably high as 0.92 eV.•The value of Ilight/Idark at 25 mW/cm2 AM1.0 illumination is ≈103.•The series resistance is affected by the illumination significantly.•The carrier concentration of CIGS thin film is 1.59 × 1015 cm−3. The electrical and photovoltaic properties of Yb/CIGS thin film Schottky photodiode were studied. A low saturation current density of 3.2 × 10−9 A/cm2 and a high zero-bias barrier height of 0.92 eV were obtained from current–voltage (I–V) measurements taken under dark and at room temperature. We observed that the I–V characteristic of the device was affected by the illumination. The device showed a good photodiode property with Ilight/Idark≈103 at the lowest illumination level of 25 mW/cm2. The value of series resistance decreased with increasing the illumination level. The values of open-circuit voltage and short circuit current density were respectively determined as 0.30 V and 78.6 μA/cm2 under the illumination level of 104 mW/cm2. The carrier concentration of the CIGS was found to be 1.59 × 1015 cm−3. The barrier height value of 0.61 eV obtained from capacitance–voltage (C–V) measurement at 1 MHz is lower than that determined from the semilogarithmic I–V plot.