Q: What will it take for India to move from being a major producer of laboratory-grown diamonds to becoming a global leader in the technology behind them?
A: India has already demonstrated that it can build a strong ecosystem around laboratory-grown diamonds, particularly in CVD growth, cutting, and polishing. India today grows and polishes a very large share of the world's laboratory-grown diamonds, but most of the MPCVD machines doing that work are not engineered in terms of designing of chambers and other peripherals. Moreover, the seeds used for growing the diamonds are imported.
That is the gap between being a producer, and being a technology leader. Value and leverage sit upstream, in the patented MPCVD reactor, the efficient microwave source, the indigenous HPHT press, and the good quality diamond seed plates. The next step is to move from being primarily a producer of diamond material, to becoming a technology owner and technology exporter.
For this, we need to develop the complete technology chain domestically -- from good quality diamond seed plates, indigenous MP-CVD reactors and HPHT press, including process control and in-situ monitoring of the recipe/methodology for high-purity diamond growth, wafer processing, device fabrication, and packaging.
Equally important is the creation of a strong research ecosystem. Universities and national laboratories can work on the fundamental science and difficult technology problems, while the industry can take these technologies towards scale, reliability, and commercialization.
India has a very large pool of engineering and scientific talent; what we need now is to bring this talent together around clearly defined technology missions.
I would like to see India move through the entire value chain: indigenous Machines → diamond growth → high-quality substrates → wafer processing technologies → device fabrication → electronic/optical/quantum devices → complete products and systems.
If we can achieve that, India will not simply be competing in the laboratory-grown market, but will be creating technologies that other countries will need to adopt.
The good news is that this gap is closing. At InCent-LGD, we built and operated the indigenous MPCVD reactor – VajraTara. This system is driven by an in-house solid-state microwave generator, and VajraKaya, India's first indigenous HPHT prototype machine. We also provided the growth recipes.
Q: If laboratory-grown production is set to expand dramatically, how and where can India build a technological edge that goes beyond jewellery-grade diamonds?
A: The honest answer is that the gem market is where the ongoing price pressure is, and the technical diamond market is where the profit margin is going.
Independent assessments put the global technical diamond supply chain is at roughly $1.65 billion this year, growing to about $4.7 billion by 2036 across more than 40 application segments. The single largest application for laboratory-grown diamonds is not jewellery; it is the diamond cutting and drilling tools, wafers for defence radar systems, and thermal management in high power computing and AI data centres.
Several of those segments are within India's reach in the near term. Polycrystalline heat spreaders for AI accelerators and high-performance computing are the most immediate, because the thermal density of that hardware has become the binding constraint.
Diamonds conduct heat about five times better than copper. Boron-doped diamond electrodes for industrial water treatment and disinfection, diamond-based optical windows, and so forth, are all markets where we already have growth capability.
Q: What are the biggest technological barriers India must overcome to make its laboratory-grown diamond ambitions commercially viable at scale?
A: I would group them into four categories.
The first is doping. The crystal lattice of diamonds is so rigid that dopants cannot be diffused in, as they are in silicon wafer. They have to be introduced during growth, or by ion implantation. Boron gives us p-type material reasonably well. Phosphorus, the principal n-type donor, remains difficult everywhere in the world. Without controlled p- and n-type regions, you cannot make diodes, transistors, or detectors out of diamond wafers.
The second is scale and uniformity. Electronic applications need large-area material with low strain, controlled defect density, and repeatable yield. That means moving from the smaller single-crystal diamond growth regime into large-area growth systems. Wafer-scale diamond substrates production requires automated growth processes, with in-situ monitoring, so that run-to-run consistency does not depend on operator skills.
The third is measurement. One cannot sell what cannot be specified/quantified. We need reference standard methods/SOPs for Crystal Quality, Strain and Defects, and Dopant Profiling at trace levels. To achieve the above, sophisticated instruments are required.
The fourth is the missing middle. We can grow diamonds, however we cannot fabricate devices from it, because there are no big-fabrication/foundry facilities with optimized processes to achieve sub nanometre (nm) level surface finish. This also requires a facility for controlled doping levels that are needed in epitaxial layers, lithography, etching, metallization, and implantation for diamond-based device fabrication. Finding the trained technical staff for this kind of work is a challenging task.
At InCent-LGD, IIT Madras, we are trying to close these gaps by working on all the above-mentioned technological challenges. The Centre is ready to help Indian Lab Grown Diamond Growers in overcoming these challenges by working together in a collaborative way.