CH3NH3PbI3 planar perovskite solar cells with antireflection and self-cleaning function layers. Issue 20 (28th April 2016) - Dudem, Bhaskar
Abstract : We report CH3 NH3 PbI3 planar perovskite solar cells with multifunctional inverted micro-pyramidal structured polydimethylsiloxane antireflection layers for enhancing the device efficiency. Abstract : We report CH3 NH3 PbI3 planar perovskite solar cells with multifunctional inverted micro-pyramidal structured (IMPS) polydimethylsiloxane (PDMS) antireflection (AR) layers for enhancing the device efficiency. These IMPS-PDMS films were fabricated via a facile and cost-effective soft lithography using micro-pyramidal structured silicon (Si) master molds formed by alkaline anisotropic wet-etching treatment of (100)-oriented monocrystalline Si substrates. The IMPS-PDMS laminated on the bare glass ( i.e., IMPS-PDMS/glass) exhibited a higher solar weighted transmittance ( T SW ) value of ∼95.2% (or the lowest solar weighted reflectance ( R SW ) of ∼4.7%) than those of the bare glass and flat-PDMS/glass, i.e., T SW / R SW ∼ 90.7/9.1 and 91.5/8.2%, respectively. Additionally, it showed a much higher average haze ratio ( H A ) value of ∼93.1% compared to the bare glass and flat-PDMS/glass ( i.e., H A ∼ 1.6 and 2.8%, respectively). By employing the IMPS-PDMS onto the outer surface of CH3 NH3 PbI3 planar perovskite solar cells as an AR layer, an improved short-circuit current density ( J sc ) value of 21.25 mA cm −2 was obtained, as compared to the reference device and the device with flat-PDMS ( i.e., J sc = 20.57 and 20.87 mA cm −2, respectively), while showing the almost same V oc and FF values as those of the reference device. As a result, the power conversion efficiency was improved from 17.17 and 17.42% for the reference and flat-PDMS devices, respectively, to 17.74% for the IMPS-PDMS device. Also, the fluorooctyltrichlorosilane-treated IMPS-PDMS surface revealed a superhydrophobic behavior with a water contact angle of ∼150° which is useful for self-cleaning applications in outdoor environments.