Journal article Open Access

High-Resolution Photoluminescence Electro-Modulation Microscopy by Scanning Lock-In

Koopman, Wouter; Muccini, Michele; Toffanin, Stefano

Morphological inhomogeneities and structural defects in organic semiconductors crucially determine the charge accumulation and lateral transport in organic thin-film transistors.

Photoluminescence Electro-Modulation (PLEM) microscopy is a laser-scanning microscopy technique that relies on the modulation of the thin-film fluorescence in the presence of chargecarriers to image the spatial distribution of charges within the active organic semiconductor.

Here, we present a lock-in scheme based on a scanning beam approach for increasing the PLEM microscopy resolution and contrast. The charge density in the device is modulated by a sinusoidal electrical signal, phase-locked to the scanning beam of the excitation laser. The lock-in detection scheme is achieved by acquiring a series of images with different phases between the beam scan and the electrical modulation. Application of high resolution PLEM to an organic transistor in accumulation mode demonstrates its potential to image local variations in the charge accumulation. A diffraction-limited precision of sub-300 nm and a signal to noise ratio of 21.4 dB could be achieved.

Files (550.5 kB)
Name Size
Accepted Version Manuscript_RSI_final_Toffanin.pdf
md5:c6b3743e75bc292f81fb51b78ac4fdf3
550.5 kB Download
139
157
views
downloads
All versions This version
Views 139139
Downloads 157157
Data volume 86.4 MB86.4 MB
Unique views 135135
Unique downloads 149149

Share

Cite as