The Deposition Environment Controlling Method: A Vapor-Phase Solvent-Assisted Approach to Fabricate High-Quality Crystalline Perovskite

The deposition environment controlling (DEC) method is explored to enhance the carrier-extracting ability of a light-absorbing layer for perovskite solar cells. Inspired by the solvent engineering, the DEC method, an exquisite-controlled approach, is applied in vapor deposition for generating the CH3NH3 PbI3. This method not only gives the excellent uniformity, coverage of the film, and glove box free for all the solution-based and annealing steps, but also provides an easy but accurate control of the additive solvent, compared with the traditional solvent engineering. Here, chlorobenzene (CB) is introduced to the sandwich deposition technique process. The vaporized CB, which does not dissolve CH3NH3 I, PbI2, and CH3NH(3)PbI(3), offers a thermodynamic driving force to rapidly and continuously generate CH3NH3PbI3 without forming the intermediate phase. The homogenous film and less defects of crystalline perovskite are yielded. As a result, the maximum grain size exceeds 1 mu m along the lateral direction and significantly improves the hole-electron dissociation. V-oc is improved to 0.99 V, J(sc) to 18.89 mA/cm(2), and fill factor to 79.03%, yielding a 14.62% efficiency.