Inverted Organic Photovoltaic Cell with ZnO Nanorod Structure

Abstract

The electrical and physical properties at the interface between the ZnO electron transport/collection layer and an organic photoactive layer play important roles in determining photovoltaic performance. Therefore, we have fabricated ZnO nanorods and optimized the coating conditions used for deposition of the ZnO seed layer, which serves as a nucleation site for crystal growth. First, the relationship between the concentration of the ZnO precursor solution (zinc acetate dihydrate and hexamethylenetetramine in methanol) and diameter of the ZnO nanorods was examined, and we showed that the diameter continuously decreased with increasing concentration, reaching a minimum of 23 nm. Further, we investigated density of ZnO nanorods and photovoltaic performance of the inverted cell as a function of the rotation speed used during the spin coating process to deposit the ZnO seed layer. A low density of ZnO nanorods was obtained when the rotation speed was low, and this caused the short circuit current density, open circuit voltage, and fill factor of the organic photovoltaics to decrease. As a result, a maximum photoconversion efficiency of 3.0% was achieved, and this value was 1.6-fold greater than that measured using a reference device containing no ZnO nanorods (photoconversion efficiency: 1.9%).

Impedance analysis of PbS colloidal quantum dot solar cells with different ZnO nanowire lengths

“…First, zinc acetate (0.55 g), methanol (10 ml), and ethanolamine (0.1 ml), which constituted the ZnO precursor solution, were thoroughly mixed using an ultrasonic washing machine, and a dense ZnO seed layer was spin-coated on an FTO-patterned glass substrate. Then, ZnO-NWs were formed by the hydrothermal method, 25,26) and the ZnOcoated FTO substrate was reacted in a heated solution comprising zinc nitrate hexahydrate (0.5 M), hexamethylenetetramine (0.25 M), polyethylenimine (0.1 M), and ammonia. The ZnO-NW length was controlled by changing the heating time in the hydrothermal method.…”

Waveguide effect enhancement of local photocurrent in hybrid organic/inorganic solar cells

“…Because of their low cost, mechanical flexibility and light weight, hybrid organic/inorganic solar cells are very promising for applications in photovoltaic devices [1][2][3][4]. They are prepared by combining organic semiconductors [5] and inorganic nanostructures [6].…”

High performance photoanodic catalyst prepared from an active organic photovoltaic cell – high potential gain from visible light

“…The so-called inverted-type OPVs have a noncorrosive Au metal as the back electrode and an ITO or a transparent front electrode. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] The inverted-type OPVs can be fabricated in ambient conditions and exhibit reasonable performance and stability especially with a stable n-type semiconductor, TiO 2 , 22-32 ZnO [33][34][35][36][37][38] or ZnS, 39 as an electron collection layer.…”