Nearly a quarter of a century ago, we wrote a review paper about the very new technology of chemical vapour deposition (CVD) of diamond thin films. We now update this review and 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 diamonds 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 be quickly 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 <i>n</i>-type dopant slowed progress substantially. Unsurprisingly, over the following decade, the enthusiasm and funding for diamonds faded, while competing materials forged ahead. But in the early 2010s, several new game-changing applications for diamonds were discovered, such as electrochemical electrodes, the nitrogen-vacancy (NV) centre defect that promised room-temperature quantum computers, and methods to grow large single-crystal gemstone-quality diamonds. These led to a resurgence in diamond research and a new hope that diamond might <i>finally</i> live up to its promise.This article is part of the theme issue 'Science into the next millennium: 25 years on'.

Synthesis of diamond by Chemical Vapour Deposition (CVD) was achieved already in the 60s, but applications became viable only in the 80–90s due to a significant improvement of the technique in which the substrate temperature was decoupled from the gas phase temperature leading to an increase of orders of magnitude in growth rates [1]. The CVD technique offered a superior control of the purity of the material with respect to natural and High-Pressure High-Temperature synthetic diamond, in particular limiting to atomic ppb the unwanted inclusion of substitutional N and N aggregates which severely deteriorate the electronic properties of the material. A huge industrial scale-up toward high technology applications was forecasted to happen in the 2000s [2], thanks to the extreme physical properties of the material, suitable for countless applications. Yet, that revolution did not happen and the field is still strongly limited by the polycrystalline nature of the material growth on non-diamond substrates, which severely impairs the electronics applications. Applications of homoepitaxially grown monocrystalline material is also strongly limited because the material itself can be fabricated with a maximum size of about 1 cm, due the availability of diamond substrates and by the cost of the production. In addition, monocrystalline samples are also affected by structural defects, such as dislocations, that degrade their optical and electronic response. Heteroepitaxial growth of large area monocrystalline samples has been recently reported [3]. Although the electronic properties of this material are still lower quality than those of the homoepitaxial one [4], optimization is underway. Heteroepitaxial material seems the only viable solution for a future widespread development of diamond applications. Nevertheless, many interesting applications of CVD diamond are already possible at present and others that offer the promise of a major breakthrough, are intensively investigated. Among the latter, the concept of diamond power electronics, although still limited by the considerable depth of the dopant (P,B) levels [5], is extremely promising. Particularly appealing is the development of fast electronics operated without need of cooling and offering the possibility of integrating diamond sensors with diamond readout electronics in compact and extremely radiation tolerant devices. In this Topic we address some of the CVD diamond applications which seem more mature. Diamond sensors for high resolution timing application have been used (Minafra et al.) in high energy experiments to reconstruct particle trajectories and measure their arrival time, profiting of the radiation hardness and the high saturation velocities of the material. A three-dimensional electrode architecture has been proposed within the TimeSpot experiment both for diamond and silicon particle detectors where the drift path of the ionization carriers towards the electrodes is strongly shortened. In this way the influence of the crystal defects as well as the charge collection times are substantially reduced resulting in some of the fastest [5] and radiation hardest [6] radiation sensors ever fabricated. Anderlini et al. summarize the results obtained so far on 3D diamond detectors Edited and reviewed by: Cinzia Da Via, The University of Manchester, United Kingdom

Diamond A diamond (from the ancient Greek αδάμας – adámas "unbreakable") is a mineral made out of carbon atoms. Diamonds have the highest hardness of any bulk (all one type) material. Because of this, many important industries use diamonds as tools for cutting and polishing things. Many of them are clear, but some of them have colors, like yellow, red, blue, green and pink. Diamonds of a different color are called "fancies". Big diamonds are very rare, and are worth a lot of money. Only 20% of diamonds are fit for jewellery. The other 80% are of lower quality. Those lower quality diamonds are called industrial diamonds, and are used to make things like drill bits and diamond saws. Even if a diamond is not of gem quality, it still has a value because It is very hard. Cut and faceted diamonds can be attractive hence their use in jewellery. Diamonds are very effective electrical insulators, but also very good conductors of heat. On Mohs scale of mineral hardness, diamonds are scored as 10 (the highest score possible). Formation of diamonds There are natural and synthetic diamonds. The Earth makes natural diamonds, and people make synthetic diamonds.

In spite of major progress in the science and technology of diamond growth, large-scale commercial production of gem-quality, large, single-crystal diamonds has not been feasible. Recently, we easily synthesized various types of gem-quality, large, single-crystal diamonds (Ib, IIa, and IIb) using a cubic high-pressure apparatus (performance enhanced by new design of double bevel hybrid anvil). Our solution saves the cost associated with the presses need, increases the region of synthesis of gem-quality, large, single-crystal diamonds, and decreases the effects of fluctuations of the pressure or temperature in the cubic sample cell. In addition, the quality and electrical properties of synthetic diamonds have been studied in detail. The synthetic diamonds have been successfully applied as diamond anvils or jewelry. This represents a relatively simple, inexpensive, and effective solution for commercial production and scientific research on gem-quality, large, single-crystal diamonds using a cubic high-press...

igures are insignificant compared to the total hours worked to exploit the field. Exploration for a new diamond field is akin to manufacturing a new HPHT press or CVD reactor, i.e., it is a preliminary step, which is, of course, important, but is insignificant in terms of total further labor input per carat. This study considers two diamond pipes mined by the DeBeers Group. These are Orapa and Jwaneng (“ Botswana ”), both situated in Botswana. In 2018, 12.2 and 11.9 million carats of diamond, respectively, were mined from these kimberlite pipes. There are 3037 and 2000 employees at Orapa and Jwaneng, respectively. Thus, the calculation of the average labor unit of these upstream diamond operations is given in Eq. (4) (3037 Orapa + 2000 Jwaneng ) ∗ 40 h per week /((12.2 + 11.9) millions of carats )/52 weeks ) = 0.43 hw/ct, (4) 3.4. Summary Summary data are presented in Table 3 . Table 3. Comparison of discussed parameters for HPHT, MP CVD, and mined diamonds. Process Origin № of people Labor input, hw/ct Quality control Productivity Mobility Preliminary work Notes HPHT Nature replication Medium 1.83 Medium High High High The cubic HPHT press, producing ∼23 carats of (near-) colorless average-sized diamonds per week HPHT Nature replication Medium 0.93 Medium High High High The cubic HPHT press, producing ∼46 carats of (near-) colorless average-sized diamonds per week 2.45-GHz MP CVD Not natural Low 3.43 High Low High Low 2.45-GHz MP reactor, with a capacity of ∼7 carats of (near-) colorless, single-crystal diamonds per week Mining Natural High 0.43 Low Very high Very low High Orapa and Jwaneng Mines, Botswana, DeBeers Group, mixed size of diamonds Open in a new tab The labor input of key DeBeers kimberlite pipes is significantly different from that of the artificial-diamond competitors. On average, it is necessary to spend less than half an hour of a miner’s work to obtain one carat of a diamond from the Orapa or Jwaneng pits, while it takes more than 1 or 3 h of grow

Comparative analysis: CapEx in diamond mining versus diamond growing, based on open data sources and experimental results - PMC Heliyon . 2024 Jun 10;10(12):e32817. doi: 10.1016/j.heliyon.2024.e32817 # Comparative analysis: CapEx in diamond mining versus diamond growing, based on open data sources and experimental results c - Author information - Article notes - Copyright and License information aHigher School of Economics, 20 Myasnitskaya st., Moscow, 101000, Russia bAdam Mickiewicz University, 1 H. Wieniawskiego st., Poznan, 61-712, Poland cSkolkovo Institute of Science and Technology, 30, Bolshoy Blvd, Moscow, 121205, Russia ⁎ Corresponding author. j.bondareva@skoltech.ru Received 2023 Apr 11; Revised 2024 May 17; Accepted 2024 Jun 10; Collection date 2024 Jun 30. © 2024 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). PMCID: PMC11225839 PMID: 38975229 ## Abstract The diamond industry has long been associated with environmental and social problems, ranging from mining practices to ethical concerns related to diamond sourcing. In recent years, there has been a growin