In this work, CdSe nanocrystals crosslinking by m-phenylenediamine (MPD) was used as an effective method for improving charge transport and enhancing the performance of CdSe/Poly(3-Hexylthiophene) (P3HT) hybrid solar cell. Fourier transform infrared (FTIR) spectra were used to illustrate the crosslinking process by diamine treatment. Binding of MPD molecules to the nanocrystals surface and replacement of initial ligands (pyridine and oleic acid) during MPD treatment were detected by FTIR. The result of nanocrystals treatment with MPD was a 30% power conversion efficiency (PCE) improvement by enhancement of short circuit current density (J(sc)) from 5.4 to 6 mA/cm(2), open circuit voltage (V-oc) from 0.7 to 0.76 V, and fill factor (FF) from 0.4 to 0.43. The J(sc) improvement was attributed to the nanocrystals bridging and charge transport enhancement. Besides, the recombination reduction and charge lifetime enhancement after MPD treatment were the reasons of V-oc increase. AFM images showed that the morphology of hybrid active layer did not change noticeably with MPD treatment. Quantum dots (QDs) crosslinking malted the hybrid film resistant to dissolution and flaking in solvents such as dichlorobenzene which provides the fabrication of multilayers. (C) 2016 Elsevier Ltd. All rights reserved.