Two-dimensional electron gas generated by La-doping at SrTiO3(001) surface: A first-principles study

Abstract

We carried out first-principles calculations to study the electronic properties of SrO-terminated and TiO2-terminated SrTiO3(001) surfaces with La-doping at the surface. We find that an intrinsic lower-lying state at the SrO-terminated surface can accommodate a two-dimensional electron gas (2DEG). By introducing La-doping at the SrO-terminated surface the energy position of the surface state and the 2DEG density can be tuned by changing the doping concentration. The higher the La-doping concentration, the lower the lower-lying state and the higher the 2DEG density. This 2DEG has a small effective mass and hopefully shows a high mobility

Patterning technology for solution-processed organic crystal field-effect transistors

“…Although solution-processed semiconducting organic crystals are ideal materials for high-performance and low-cost devices, most processes involved in organic crystals grown on flexible substrates do not have a patterning capability. Demonstrating the application of organic semiconducting crystals deposited from a solution in flexible OFETs, we applied our technique to fabricate patterned organic crystals on flexible PEN substrates [104]. As shown in figure 6(a), device arrays were fabricated on a PEN substrate with the bottom-gate top-contact structure.…”

“…(i) The AFM profile taken across the broken line over a patch in (h), consistent with the length of the C 8 -BTBT molecule. (Reproduced with permission from [24, 104] © 2012 Elsevier and © 2013 Authors. )…”