Detection of Charge Storage on Molecular Thin Films of Tris(8-hydroxyquinoline) Aluminum (Alq3) by Kelvin Force Microscopy: A Candidate System for Hig

Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq₃) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq₃ films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq₃ films, even for high hole and electron densities of >10¹² cm^–2. We show that this finding is consistent with the very low mobility of charge carriers in Alq₃ thin films (<10^–7 cm²/(Vs)) and that it can benefit from the use of Alq₃ films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq₃ molecules as the floating gate are fabricated and measured, showing durability over more than 10⁴ program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10¹³ cm^–2. These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells.

Reference:

Detection of Charge Storage on Molecular Thin Films of Tris(8-hydroxyquinoline) Aluminum (Alq3) by Kelvin Force Microscopy: A Candidate System for High Storage Capacity Memory Cells ( 27 de febrero)

Sarah Paydavosi, Katherine E. Aidala, Patrick R. Brown, Pouya Hashemi, Geoffrey J. Supran, Timothy P. Osedach, Judy L. Hoyt, and Vladimir Bulović

Nano Letters Article ASAP [online] http://pubs.acs.org/doi/abs/10.1021/nl203696v