The power conversion efficiency enhancement of InAs quantum dots solar cell is investigated by using sal-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. (C) 2014 Elsevier B.V. All rights reserved.