Supplementary material from "Diamond Thin Films: A 21st Century Material. Part 2: A New Hope"

Nearly a quarter of a century ago, we wrote a review paper about the very new technology of chemical vapour deposition of diamond thin films. We now bring the story up to date by describing the progress made – or not made – over the intervening years. Back in the 1990s and early 2000s there was enormous excitement about the plethora of applications that were suddenly possible now that diamond could be fabricated in the form of thin films. Diamond was hailed as the ultimate semiconductor, and it was believed that the few remaining problems would quickly be solved leading to a new ‘diamond age’ of electronics. In reality, however, difficulty in making large-area diamond wafers, and the elusiveness of a useful n-type dopant, slowed progress substantially. Unsurprisingly, over the following decade, the enthusiasm and funding for diamond faded, while competing materials forged ahead. But in early 2010’s, several new game-changing applications for diamond were discovered, such as electrochemical electrodes, the NV-centre defect which promised room-temperature quantum computers, and methods to grow large single-crystal gemstone-quality diamond. These led to a resurgence in diamond research and a new hope that diamond might finally live up to its promise.