Physics and Applications of Novel Gain Materials
Authors: Calvez Stephane , Rorison Judy , Guina Mircea , Alexandropoulos Dimitris , Balkan Naci 
Published: April 2013

If silicon and its associated oxides are the enabling materials for mainstream micro‐electronics, III–V semiconductors have proven to be key alloys for opto‐electronic devices and specialized electronics. Indeed, these semiconductor compounds are the basis of laser diodes and detectors used in optical communications (being for long‐haul transmission or within datacenters), and of the high‐frequency electronics embedded in wireless communication systems. Furthermore, they are also becoming of strategic importance in major emerging or future markets, namely through visible LEDs for solid‐state lighting and concentrator‐based multi‐junction solar cells.

All these developments critically depend on the availability of suitable materials and the ability to engineer their structural/electronic/optical properties to enable new functionalities or improve device performance. The introduction at the end of 1990s of the highly‐mismatched III–V alloys, in which a group III or V element of very dissimilar size to the other elements of the compound is incorporated, offered new opportunities in that respect since these novel semiconductors permit the range of useful III–V compositions and bandgaps to be extended in an unusual way. This deliberate choice to include a mismatched element resulted in growth challenges, but also gave rise to new physics to understand their unique opto‐electronic properties and how to exploit these in full to make advanced and/or new devices. This active field research has been dominated by the reports on the III–V nitrides. These can be either (Al)(In)GaN compounds, which present high nitrogen content and wide bandgap (1.1 eV (InN) < Eg < 6.2 eV (AlN)) and are mostly studied for solid‐state lighting applications, or the other III–V–N alloys, which include a low nitrogen content (<10%) and possess a small bandgap (Eg < 1.4 eV) and whose primary drivers are telecommunication and more recently intermediate band solar‐cell applications. If the activity on the latter materials carries on, a new strand is emerging: the III–V bismides.

This issue of physica status solidi contains a collection of articles presented during the Symposium T of E‐MRS Spring Meeting 2012, entitled “Physics and Applications of Novel Gain Materials Based on Nitrogen and Bismuth Containing III–V Compounds”. The symposium was a follow up meeting to similar sessions held at E‐MRS 2007 and 2010. This meeting organized in collaboration with the COST Action MP 0805 attracted more than 100 participants as in 2010, indicating that this topic is of high interest for both fundamental and more applied science. The symposium included 58 oral presentations, among which 12 were invited and 51 poster presentations on a variety of dilute nitride and bismide alloys as well as on InGaN compounds. These presentations summarized the latest progress on material growth, on the assessment of the structural, electronic and optical properties of these alloys, as well as their use in various opto‐electronic devices.

The Guest Editors

Stephane Calvez, Judy Rorison, Mircea Guina, Dimitris Alexandropoulos, and Naci Balkan