Effect of electron transport layer crystallinity on the transient characteristics of inverted organic solar cells

Abstract

We present how the crystallinity of the electron transport layer can dramatically influence the transient characteristics of organic solar cells. We employed an inverted cell structure using TiOx prepared by atomic layer deposition as an electron transport layer. The device possessing the amorphous phase TiOx exhibited a continuous increase in the device characteristics upon continuous illumination at ambient, which is attributed to the filling of shallow electron traps within the amorphous phase TiOx upon illumination. In contrast, the characteristics of the device with the crystalline phase TiOx showed a negligible increase upon continuous illumination.

Built-in potential shift and Schottky-barrier narrowing in organic solar cells with UV-sensitive electron transport layers

“…38,39 We therefore also conclude that changes in trapassisted recombination at the TiO x interface play a relatively minor role in the change in device output. 40,41 This is consistent with the traps being electrically inaccessible, which is implied by the very long ''memory'' of such TiO x interlayers and our inability to reproduce the resistivity change by simply injecting carriers directly into the TiO x .…”

Enhancing performance of inverted polymer solar cells using two-growth ZnO nanorods

“…Within the development of polymer solar cells that seek for stability and lifetime, an inverted structure with reverse electron flow has shown its significance recently [4][5][6][7][8][9][10][11][12][13][14]. In conventional structures, poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PPS), a conductive polymer, which is frequently deposited as the hole transport layer (HTL), is found to cause corrosion to ITO.…”

High‐speed atmospheric atomic layer deposition of ultra thin amorphous TiO2 blocking layers at 100 °C for inverted bulk heterojunction solar cells

“…Of all the different possibilities, ALD has great promise because it is capable of producing high quality conformal thin films at low temperatures and in a single step. It has been used successfully in bulk heterojunction cells as well as in other types of solar cells . However, conventional ALD has low deposition rates and requires vacuum processing, thus limiting its industrial use, although it is well‐suited to batch processing of ultrathin layers, for example, in the microelectronic industry .…”