Visualization of Carrier Transport in Luminescent Polymer Thin Film by Using Transient Photoluminescence Decay Imaging. Issue 12 (11th March 2020)

• Record Type: Journal Article
• Authors: Manaka, Takaaki; Taguchi, Dai; Chiang, Tai-Chin
• Other Names: Lee Cheon guestEditor.; Choi Ji-Won guestEditor.
• Is Part Of: Physica status solidi. Volume 217:Issue 12(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-11
• Subjects: carrier mobility -- organic semiconductors -- photoluminescence; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201901031
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : Transient photoluminescence (PL) decay imaging is conducted for visualizing carrier transport in luminescent polymer semiconductor thin films. The method is simple, but enables a real‐time observation of carrier motion on the scale of several millimeters in luminescent thin films. Decrease in the PL intensity of the channel region in organic field‐effect transistor (OFET) is observed in accordance with the device operation. Upon application of pulse voltages to the source electrode for carrier injection, the transient PL decay motion is visualized using a conventional charge‐coupled device (CCD) camera. By analyzing the PL decay motion, hole and electron mobilities of poly(9, 9‐di‐ n ‐octylfluorene‐alt‐benzothiadiazole) (F8BT) thin film are evaluated as 1.3 × 10 −4 cm 2 (V s) −1 and 3.2 × 10 −5 cm 2 (V s) −1, respectively. Mobility anisotropy is also visualized by using round‐shaped electrode as the source electrode, and the difference of mobility anisotropy for hole and electron of F8BT is clearly identified. Abstract : Anisotropic carrier transport in organic luminescent polymer semiconductor thin film is directly visualized using real‐time photoluminescence (PL) decay imaging. Difference in the mobility anisotropy for hole and electron is clearly observed. That is attributed to the difference in the electron distribution in the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels.