Enhanced performance of surface modified InAs quantum dots solar cell by a sol–gel grown tantalum pentoxide antireflection coating

•A sol–gel synthesis of Ta2O5 is developed with a refractive index of 1.9.•The antireflection scheme was characterized by various optical measurements.•The thickness of Ta2O5 layer was optimized to yield the maximum efficiency.•An enhancement of 41% on the power conversion efficiency is obtained.

The power conversion efficiency enhancement of InAs quantum dots solar cell is investigated by using sol–gel grown tantalum pentoxide (Ta2O5) single layer antireflection coatings. A sol–gel synthesis method is developed to grow Ta2O5 films with a refractive index of 1.9. A power conversion efficiency enhancement of 41% is obtained by using a single Ta2O5 layer, while the enhancement in the external quantum efficiency is nearly 60%. The substantial improvement in the device performance is attributed to the increase in the generated photocurrent without degrading the open circuit voltage. The enhancement in the device performance is due to the significant reduction in the reflection of the incident photons. Furthermore, the enhancement is found to depend on the Ta2O5 film thickness.