There are various methods to produce graphene materials, such as mechanical exfoliation of graphite, liquid-phase exfoliation and reduction of graphene oxide (GO), each with its own set of advantages and disadvantages. Chemical vapor deposition (CVD) is a method of producing graphene that has attracted much attention in the last decade and despite several shortcomings, is considered a leading approach to manufacture graphene, especially for applications like high-performance electronics and sensors, as it can yield high quality graphene sheets with a low defect count and good uniformity.
The CVD process
Generally speaking, the CVD method is based on gaseous reactants that are deposited on a substrate. The graphene is grown on a metallic surface like Cu, Pt or Ir, after which it can be separated from the metal and transferred to specifically-required substrates. When the gases contact the substrate inside the heated reaction chamber, a reaction occurs that creates a film of material on the substrate. The process can be simply explained as carbon-bearing gases that react at high temperatures (900–1100 °C) in the presence of a metal catalyst, which serves both as a catalyst for the decomposition of the carbon species and as a surface for the nucleation of the graphene lattice.
As was mentioned before, conditions like temperature, pressure, duration of time and many more can have a significant influence on the process and so must be carefully monitored.
Advantages and disadvantages
CVD can yield high quality graphene, with common characteristics that may include high homogeneity, imperviousness, high purity, fine grains, good control over layer number and more. However, CVD also comes with several disadvantages - namely a relatively high price of the equipment, toxic gaseous by-products and, as stated before, it is a rather sensitive process that is easily influenced by parameter changes. It is important to note that while CVD is a rather expensive method compared to other methods to produce lower-quality graphene, it is still probably the best way (to date) to acquire high quality graphene, since other ways to do that are even more expensive or complicated.
In addition, the separation (or exfoliation) of graphene from the substrate is known as challenging and it is tricky to accomplish without damaging the structure of the graphene or affecting the properties of the material. Another harrowing task is the creation of a uniform layer of graphene on a substrate, something that is continuously proving to not be easy at all.
Some approaches were and are still being developed to overcome this issue, like modifying the concentration of gases and incorporating spin coating methods, but this remains a challenge. However, despite these challenges, it is important to note that CVD is widely considered as an important and promising method to produce graphene, which is already in use, and will probably be even more so in the future, once further advancements are made. It is noteworthy that CVD is already a dominant manufacturing route for many other nanomaterials, and will assumably be in extremely common use once progress is made to resolve the issues that are currently hindering its acceptance.
While using the CVD method to produce graphene is definitely one the leading approaches in the world, it is still hindered by the challenges mentioned above. Thus, it is currently mostly limited to relatively small volumes and mainly restricted to R&D and academic uses.
However, graphene sheets produced via CVD methods are used in several applications like sensors, touch screens and heating elements. It is believed that once better answers are found to the questions of price and handling of CVD graphene, many more applications will start to appear.
Looking to buy CVD graphene sheets?
If you are interested in buying CVD graphene sheets, check out the Graphene Catalog that lists various CVD produced graphene sheets from several producers.
The latest CVD graphene news:
This is a sponsored post by planarTECH
Remember, when investing your capital is at risk.
Since planarTECH's business encompasses the entire graphene value chain (from academics to producers to application developers) the company would like to call out to all graphene professionals and others who may be interested to take part in this exciting graphene crowdfunding project.
planarTECH is aiming to raise at least £350,000, but even small investments (as little as £10) are welcome and encouraged since the company is set on making this a graphene community endeavor. Don't miss your chance to be a part of an early stage and promising graphene technology company!
UK-based planarTECH has launched an equity crowdfunding campaign on Seedrs, as part of Graphene-Info's Graphene Crowdfunding Arena. planarTECH aims to expand its current business and also initiate new graphene endeavors. Investors are now able to participate in this financing round.
Here's our interview with planarTECH's co-founder and CEO, J. Patrick Frantz - who explains the company's technology, business and future plans.
UK-based planarTECH has launched an equity crowdfunding campaign on Seedrs, as part of Graphene-Info's Graphene Crowdfunding Arena. planarTECH aims to expand its current business and also initiate new graphene endeavors. Investors are now able to participate in this financing round, already at 39% only a few hours after it opened!
planarTECH, founded in 2014, supplies CVD equipment for the production of high quality graphene sheets, as well as other 2D materials. The company was focused on research institutes, and already sold over 65 systems with a customer list that includes Manchester University, the University of Cambridge, Stanford University and the National University of Singapore.
UK-based planarTECH is launching an equity crowdfunding campaign at on Seedrs, as part of Graphene-Info's Graphene Crowdfunding Arena, and the company now released its first investor video pitch that summarizes the business and technology:
planarTECH is the first company to apply to our Graphene Crowdfunding Arena, and potential investors can currently pre-register for exclusive early access to this campaign. The first step should be to join Seedrs as an investor (which will also enable the participation in future graphene campaigns) and then to apply to planarTECH’s investment page as an interested investor. The company's campaign will go live soon!
This is a sponsored article by Dr Richard Collins, IDTechEx
Graphene is on the cusp of significant market growth; the opportunities are exciting and diverse, each with significant potential. Graphene and 2D Materials Europe 2020 (13-14 May, Berlin) is the largest B2B event on the topic with a dedicated focus on the commercial frontiers. www.GrapheneEurope.tech
There is often confusion surrounding the types of graphene, commercial status, and their target markets. This article will briefly summarise each and showcase what to expect at this event.