Microstructural Engineering of Solution-Processed Epitaxial La-Doped BaSnO₃ Transparent Conducting Films

Abstract

Epitaxial La-doped BaSnO3 (BLSO) thin films were fabricated on a SrTiO3 (100) substrate by a cost-efficient and scalable solution deposition method. Microstructures and optoelectronic properties of the BLSO thin films can be controlled by the metal cation concentration (MCC) of the initially used precursor solution. It is found that thin films with a denser microstructure, lower resistivity, higher optical transmittance, and good thermal stability can be obtained from the solution with a lower MCC. The growth mechanisms of the initial nucleation are explained in detail for different MCC-derived thin films. Most of all, the highest room-temperature carrier mobility with the value of 53 cm2 V–1 s–1 was achieved among all solution-processed donor-doped BaSnO3 thin films to date. The herein proposed microstructural engineering of the BLSO thin films contributes a sensible and feasible avenue to optimize the optoelectronic performance of transparent conducting thin films by a simple solution approach.

Chemical Synthesis of La0.75Sr0.25CrO3 Thin Films for p-Type Transparent Conducting Electrodes

“…This is also reflected on the residual resistivity ratio (RRR) calculated from ρ­(300 K)/ρ­(150 K) resulting in smaller values (0.024) than MBE films . The same trend has been reported for other CSD-processed n -type TCO perovskite thin films when compared to their vacuum-processed counterparts. ,,,,, …”

“… 24 The same trend has been reported for other CSD-processed n -type TCO perovskite thin films when compared to their vacuum-processed counterparts. 33 , 35 , 36 , 38 , 52 , 53 …”

“…Nevertheless, when evaluating the suitability of an oxide material to be used as a TCO, along with high electrical conductivity and optical transmittance, it is important to consider cost-effective and sustainable processing techniques. Over the past decade, significant progress has been made to enable the production of high quality metal oxide thin films using chemical solution deposition (CSD), a well-established, inexpensive, and potentially scalable route that offers the possibility to prepare epitaxial perovskite oxides and perform simple compositional tuning by identifying compatible precursor salts and solvents. − In fact, successful growth of solution-processed n -type TCO perovskite films based on M-doped BaSnO 3 (M = La, Pr, Nd, Sb) − and La-doped SrTiO 3 , has been previously reported. However, the study of CSD p -type TCO perovskite films is at its infancy.…”

Tungsten-doped barium stannate as a transparent conducting film

“…5(a), was detected ranging from 250 to 6000 nm for the prepared BSWO thin films. In comparison, the transmittance of our previous (Ba,La)SnO 3 (BLSO), 33 Ba(Sn,Sb)O 3 (BSSO), 18 and Sn-doped In 2 O 3 (ITO) 4 thin films are also introduced. The overall transmittance shows a depressing tendency with the increment of W-doping content owing to the enhanced carrier reflection.…”

Combined Spectroscopy and Electrical Characterization of La:BaSnO$_\text{3}$ Thin Films and Heterostructures

“…However, the reported µ e in La:BaSnO 3 thin films have only reached a maximum value of 183 cm 2 V −1 s −1 (n 1.2 × 10 20 cm −3 ) for epitaxial films grown by molecular beam epitaxy (MBE) [33]. Other growth techniques resulted in the following electron mobilities: 140 cm 2 V −1 s −1 (n 5.2 × 10 20 cm −3 ) for pulsed laser deposition (PLD) [27], 121 cm 2 V −1 s −1 (n 4.0 × 10 20 cm −3 ) for high-pressure magnetron sputtering [36], and 53 cm 2 V −1 s −1 (n 2.0 × 10 20 cm −3 ) for chemical solution deposition [39]. Various strategies to improve the mobility in La:BaSnO 3 epitaxial films have been explored.…”