What is a PhD? A primer for curious students
I am often asked by my students what a PhD is. This blog is intended to sketch out the main points as a resource for either them or anyone asking the same question of the internet. My focus is Chemistry in the UK, but some of the points will apply to other subjects and other countries.
The basics
A PhD is the highest possible academic qualification, and is a research degree which takes 3-4y full time to complete. Anyone with a PhD has demonstrated to experts that they have made a contribution to knowledge. This might be a new fact (“these molecules now exist”, “this new synthesis can be used to make an old molecule more economically”), but it could also be new relationships between facts (“while we used to think X, a closer look at this data suggests we should consider Y”, “if our modelling accounts for relativistic effects differently, our predictions about Y become more accurate”).
Assessment is normally by thesis and a “viva voce” exam, in which the student answers detailed questions about their work. The normal outcome of this is to pass with corrections.
Three Project Structures
The traditional pattern of work in Chemistry is that you become part of a research group who are doing related projects, normally led by one academic. Projects evolve from the recent work of the group and the general direction of the field. Often a new PhD student would start working in parallel with a senior PhD student or a postdoc before becoming more independent in later years of their project.
Funders are increasingly imposing cosupervision models on Universities, in which PhD projects are supervised by two academics. The structure of these projects can vary quite significantly. Often the project sits mostly in one group, but involves well-defined work in another group (e.g. to use an unusual piece of equipment or to exploit a particular expertise). Sometimes the project is split more evenly - it’s very much driven by what the research question is.
Strategic funding for “Centres for Doctoral Training” (CDTs) sometimes create an unusual cohort model of PhD project. Often, these involve recruiting a class of 10+ PhD students each year into a field (Liverpool has one for Digital and Automated Materials Chemistry, for example). The class gets elements of taught course training alongside traditional research project work in the field. Some people like the ready-made community this builds for a student, but other people resent how the taught course takes time away from the research project.
To stay or to move?
The traditional view is that there is a benefit to moving between institutions between your degree and your PhD. A new place has new ways of doing things, and it is good to broaden your experience. That said, there has always been a strong recognition that sometimes the only project you want is in one place, and if that’s where you currently are then you should stay.
There is a growing acknowledgement that people don’t always have the desire or ability to move, though. Family commitments or chronic medical conditions are two such cases. My own view is that moving is worth taking seriously if you can, not least because it widens your options. Your current institution has one pool of PhD studentships, but other institutions have other pools.
Money
PhD funding is competitive, but it is available. The best single source of information about studentships is on findaphd.com . It can be good to browse through listings for a few hours to get a feel for how academic projects are set up. Funding amounts vary by time and source, but ball-park figures are helpful. As well as covering the University’s fees, the main UK funder UKRI currently (2026) gives students about £21,000/year to live on. This is tax-free, and in most cities will give you an ok standard of living. It is very common for PhD students in Chemistry to do lab demonstration work for something like a day a week during term-time, too, which is often pretty well-paid.
International students will have a harder time finding funding in the UK. There are funders who support international students, but all the advertising is built around advertising to domestic students. Looking will take longer, sorry!
I would recommend that no-one ever considers doing a self-funded PhD: if your options are to self-fund or to leave academia, the correct choice is to leave academia. Unfortunately, this choice will - on a simple statistical basis - happen to a lot of very good students. There are fewer places than applicants, and it is very normal for excellent candidates to be unable to find funding.
How to apply
The normal time to apply would be around/after Christmas of your final year of study, as this normally catches the adverts for projects starting in the following academic year. Funding coming from research grants is less predictable, and adverts for these projects are more ad hoc. It is worth browsing listings from time to time to catch these. CDTs often have much clearer application procedures, which will normally be outlined on their webpages.
It would be normal to send a potential supervisor a short, polite email asking to discuss the project. To give some idea of the tone and content, this is probably about the right level of detail in my opinion. If you have other particularly distinctive CV items, you should list these briefly as well.
Dr XXX,
I am a final-year MChem student at the University of YYY. I saw the PhD project you advertised on findaphd.com about ZZZ, and am interested in applying. Might we talk sometime in the next few weeks about it?
I attach a copy of my CV. I note that my grades are >70% in organic chemistry, and that my project work this year is about polymer cross-linking.
Sincerely ,
[name]
Supervisors want to hire good people, so finding the right PhD student is a high-value activity for them. It used to be very common for prospective applicants to visit the University, but with video calls this has become more unusual (make sure you have a quiet space for video calls). You should expect to answer questions about your work (especially project work), and to show signs of having read some recent papers by the group relevant to the project. It is ok to ask for reading suggestions when emailing potential supervisors, but you should also expect to do some leg work finding their recent publications. If you don’t have access to the journals (e.g. because you have graduated) I strongly recommend that you explain this to a supervisor and ask for copies of a few recent papers you might read.
Your grades will be important to supervisors - having a 2:i (or being on track for a 2:i) is normally a requirement to secure funding, and higher grades are better. Project experience will likely be important, too. Supervisors recognise that student choice over projects is often restricted, and are not expecting a perfect fit with their own area. But exposure to the ‘day-to-day’ work of being in the lab will make your application stronger. This means that BSc graduates are normally less competitive than MChem graduates; it is very unusual in Chemistry to enter a PhD from a BSc.
Bluntly, lots of people have both good grades and project experience. The impression you give of yourself when meeting the supervisor is therefore important. To be polite and friendly is important. To show that you want to work with people rather than in competition with them is important. To respond to someone else’s contributions in a conversation is important. A good supervisor will spend months of their life making you a better scientist; help them want to do that.
The other way to distinguish yourself is to find sincere technical ways of talking about the reading you’ve done. Questions which aren’t aiming to show that you have simply read a recent paper, but rather that something about the paper made you curious. Why this analytical technique (and not that one)? Why that functional group (rather than that one)? Have you tried this with other metal centres? If nothing about the papers makes you feel some sense of curiosity, it’s probably worth asking yourself whether this project is the right fit for you.
Underpinning all of this is the idea that a PhD is a very academic endeavour. You should expect most of the discussion to be very squarely about technical scientific questions. Depending on the project, this might mean that it’s worth brushing up on certain areas of undergraduate topics.
Talk with the group
Most supervisors will offer you a chance to meet the group on your own (i.e. without the supervisor standing around). If they don’t offer, you should ask because the group will be the core experience of your PhD. You will see your group every day, and certainly much more frequently than you’ll see your supervisor. Most of your questions should be about figuring out the feel of the wider environment. A few reasonable questions you might consider:
What do you like about your project?
What’s the most difficult bit of the work?
Is there a culture of working weekends here?
What is the city like?
How often do you see [supervisor]?
How do you find the wider Department?
What are you hoping to do after this?
Identity and Discrimination
I believe that most Chemistry Departments are trying very hard to diversify their communities, but I hold this belief from a position of considerable privilege. Even holding this privilege, it is hard to know how to ask meaningful questions without being confrontational. “How come all your professors are men?” is a difficult question to ask gently.
I have friends who say that they look for Athena SWAN awards when looking at Departments (it’s not a perfect system, but it tells you something when a Department doesn’t have any awards). While the Race Equality Charter hasn’t yet become standard, it may occupy a similar signalling function in the future. Glancing through staff photos often gives a quick sense of certain visible elements of diversity. A University’s Disability pages are often set up to allow prospective (undergraduate) students to contact the team before applying.
But the extremely awkward truth is that basically the whole system rests on your supervisor. A supervisor who wants to support you will make it work. I regularly see socially conservative colleagues banging the drum for their students’ needs - not really because of a wide social justice concern, but because of a narrower desire to support their students. I have also seen “woke” colleagues do very little to support their students, despite having a similar outlook on lots of social issues. There is no way to escape the fact that a PhD is ultimately a training under the supervision of an academic. Most of this training will be hard, technical immersion in the field. But some of the training is about the social norms implicit in academic communities; sometimes those norms are Bad.
The normal situation is that the professional relationship between a student and a supervisor is an extremely positive part of the PhD, and this helps everyone to deal with things if/when they come up. If that relationship breaks down, there are mechanisms for switching supervisor. The mechanisms are clunky, though, and would normally involve switching project as well. Again, this is unusual: the typical Chemistry PhD is academically demanding but also professionally supportive.
Job Prospects
A PhD is normally required to get an academic job, but it is not enough. For traditional research careers, a PhD would normally be followed by two postdoctoral roles before a lectureship. The current academic job market is also completely wild, and even exceptional candidates routinely struggle to get jobs.
My hand-on-heart advice to anyone considering an academic career is to only do the next step if you want to enjoy that next step. If you want to do a PhD, go for it! If you don’t really want to do a PhD but you want to be a professor, absolutely do not go for it! The odds are against you at every stage, and in that context the only reasonable response is to enjoy the journey.
In that framing, a PhD is a highly marketable qualification - it shows mastery of your discipline, as well as hard grind and grappling with uncertainty. The softer skills you gain along the way are often extremely valuable, too. That said, if your main goal is to earn money then the reduced earnings during the 3-4y period of study will lower your income relative to most good jobs.
So only do it if you want to do it. But if you do want to do it, go for it.
Other sources of support
Current students should always talk with other people if they’re thinking about doing a PhD. If you’re currently doing a research project, talking with other people in the group can be useful Lab demonstrators are also often well-placed to say something helpful. Lecturers or Personal Tutors are often able to talk things over with you, too, if you are prepared to ask.