We utilize an adsorption/desorption process between the excess acetic acid in solution and the bound oleate ions on the surface of CdSe quantum dots to achieve ligand exchange process in the hybrid film of poly (3-hexylthione) (P3HT): CdSe quantum dots (QDs). By this post-deposition ligand exchange method, we achieved hybrid solar cells with power conversion efficiency of nearly 2% at low annealing temperature (120 degrees C). Compared to the thiols that are widely used in hybrid solar cells, acetic acid shows its advantages of environmental friendliness, non-toxicity and mild odors. As such, our method is attractive for future hybrid solar cell applications. (C) 2013 Elsevier B.V. All rights reserved.