I'm a PhD candidate too - my contract is finished now, but I am still writing my thesis. So I am currently at the awkward intersection of finishing a thesis and looking for a job.
My PhD focus is in applying time-resolved spectroscopic techniques to study the excited state dynamics of molecules. Basically, these are experiments in which a pulsed laser is used to excite the sample and a second probe light is used to measure a change in the absorption in response to the light. By measuring these changes in the absorption as a function of time, and applying quantum chemical methods to calculate the spectra of potential intermediates, one can sort of recreate a movie of what the molecule is doing after it absorbs light with a time resolution of femto to picoseconds. The materials that I study are organic dyes that are useful for microscopy, as well as molecules that respond to EUV light for applications in photonanolithography (for making the very small transistors in computer chips).
I am also an "amateur" scientist when it comes to biology, as many of my hobbies are nature-based and it's not like I can turn off the science bug when it comes to hobbies.