Towards bipolar tin monoxide: Revealing unexplored dopants

Abstract

The advancement of transparent electronics, one of the most anticipated technological developments for the future, is currently inhibited by a shortage of high-performance p-type semiconductors. Recent demonstration of tin monoxide as a successful transparent p-type thin-film transistor and the discovery of its potential for ambipolar doping, suggests that tin monoxide-an environmentally friendly earth-abundant material-could offer a solution to this challenge. With the aim of enhancing the electronic properties, an extensive search for useful dopant elements was performed. Substitutional doping with the family of alkali metals was identified as a successful route to increase the concentration of acceptors in SnO and over ten shallow donors, which, to the best of our knowledge, have not been previously contemplated, were discovered. This work presents a detailed analysis of the most promising n-/p-type dopants-offering new insights into the design of an ambipolar SnO. If synthesized successfully, such a doped ambipolar oxide could open new avenues for many transparent technologies.

Functional Oxides for Photoneuromorphic Engineering: Toward a Solar Brain

“…In any case, oxides generally exhibit an important doping asymmetry and bipolar oxide semiconductors [135] represent only a small subset (e.g. CuInO 2 [136] , SnO [137] , Ga 2 O 3 [138] , Ni x Cd 1−x O 1+δ [139] , SnNb 2 O 6 [140] , ZrOS [141] ).…”

Bridging the p-type transparent conductive materials gap: synthesis approaches for disperse valence band materials

“…15,18 These materials possess a VBM with significant contributions from anion p-states, which for nonoxide anions are more delocalized than the 2p orbitals of oxygen. 18 Materials such as sulfides, iodides, and especially phosphides 13,15,16,19,22 were found via highthroughput screening and first-principles calculations to commonly have m à h < 5 m e , with phosphides including many examples <1 m e , owing to the metal-p and phosphorous-p orbital mixing at the VBM. 15 Notable p-TCM candidates in these material classes are boron phosphide (BP), 15 copper iodide (CuI), [22][23][24] CuAlS 2 , 25,26 (Zr,Hf)OS, 16,27 and Mg:LaCuOSe.…”

“…In this review, we present an overview of the experimental techniques and synthesis approaches reported on DVMs with the aim to bridge the gap between computational and experimental works on p-TCMs. The authors note that while oxide materials with promising p-type conductivity and transparency properties have received attention in the recent computational literature, 14,19 we focus herein on materials beyond oxides, as oxides are considered well-known chemistries with several synthesis approaches already at advanced stages of development.…”

Electronic properties of the Sn1−xPbxO alloy and band alignment of the SnO/PbO system: a DFT study

“…Besides all the above efforts, the structural and electronic properties of SnO have also been studied in the past using density functional theory (DFT). Recently, an extensive study for the most promising n-and p-type dopants has been published 20 where Li, Na, K, Cs, Rb and Ag were were found to act as shallow acceptors and therefore were proposed for p-type doping of SnO at a substitutional position, replacing Sn. Additionally, isovalent Sn 1−x M x O (M = Mg, Ca, Sr, Zn) alloys have been examined theoretically for the application of SnO as a thin film based solar cell 2 .…”

“…Contrary to efforts on Pb doping of SnO 2 , Pb x Sn 1−x O 2 and the PbO 2 /SnO 2 heterojunction (HJ), there are very few investigations on Pb doping of SnO and the properties of the ternary oxide Pb x Sn 1−x O. Pb doping of SnO was investigated experimentally by Liao et al 16 who observed a small increase of the optical band gap by 0.7 eV (to 2.75 eV) and a decrease of the hole mobility, attributed possibly to trap formation. The preparation of SnO/ PbO solid solution and its properties were examined by Kwestroo et al 24 , whereas Lim et al 20 investigated the properties of layered SnO and layered PbO for energy applications. They concluded that SnO is a better material for electron transfer and a better catalyst for hydrogen evolution than PbO.…”