McGehee Group

Stanford University | Stanford Materials Science & Engineering | Center for Advanced Molecular Photovoltaics (CAMP)

Frequently Asked Questions

1. What kind of research do you plan to do in the coming years?

The overarching project that now unifies most of what the group does is making tandem solar cells with either organic or perovskite solar cells stacked on top of either silicon or CIGS solar cells. We have made 18.6% efficient tandems with CIGS and perovskites and hope to break 20% efficiency soon. The group is broken up into sub-teams that are working on different aspects of this project. Their research is described elsewhere in this website. While our research has a very clearly defined application, members of the group spend most of their time doing science that enables us to understand how the solar cells work so that we can improve them in a rational manner that only involves a minimal amount of trial and error.

It is hard to predict what new ideas might emerge over the next several years, but they will probably lie at the intersection between organic electronics, perovskite semiconductors, nanotechnology and renewable energy.

2. How do you manage the group?

The group is usually broken up into four or five subgroups that work on topics such as transparent electrodes, long-term stability of polymer solar cells, device physics and morphology of polymer bulk heterojunctions, fundamental science of perovskite semiconductors, and tandem solar cells. Prof. McGehee sometimes meets with individuals, but usually meets with an entire subgroup, which normally consists of two to four people. We have some group-wide meetings and lots of meetings with collaborators, such as Hema Karunadasa (Chemistry), Alberto Salleo (Materials Science), Mike Toney (SLAC), Jean-Luc Bredas, Aram Amassian and Pierre Bueajuge (KAUST), Gui Bazan, Queyen Nguyen and Alan Heeger (UCSB), Michael Graetzel (EPFL), Mark Thompson (USC) and Tonio Buonassissi (MIT).

When students join the group, they usually spend their first nine months learning from the older students and working on a small project of their own. After they are done with their first year of classes, they sometimes take over the project of a graduating student, but usually come up with their own idea and go in a new direction.

Members of the McGehee group work together very closely with each other and with our collaborators. The tight network of people makes it possible to do things that require a wide range of expertise. Although students do help each other a lot, the group is run in such a way that no one becomes super specialized. Most people become highly skilled in a couple of areas, but are still competent in many other areas as well.

3. How many students will you be taking this year and how do people join the group?

Professor McGehee takes two or three new PhD students every fall. Students who are already at Stanford and interested in joining the group should let him know by mid-October since the selections are usually made in the Fall.

4. Do I need to have a degree in Materials Science to join the group?

No. Members of the group have come from the Materials Science Department, the Chemistry Department, the Electrical Engineering Eepartment and the Applied Physics Department. Students have come into the group having majored in any one of these subjects plus Mechanical Engineering and done quite well. When someone joins the group, Professor McGehee assesses that person's strengths and weaknesses and advises them on what courses to take in order to have the right background for doing the research. He did not know what a semiconducting polymer was when he started his PhD research with Alan Heeger, so you shouldn't worry about not having the right background.

5. What do you look for when you are selecting students?

While I like to see that a prospective student has done well in their courses at a strong undergraduate institution, there are other factors that I look for as well. I look for candidates with extensive research experience and strong recommendation letters from their supervisors. I also look for candidates that have excelled in extracurriculars, such as sports, music or service to charities or environmental organizations. I particularly like candidates who have demonstrated leadership and have excellent communication skills. I look for candidates who would love to do science even if it had no application, but who choose to devote their career to something that will make the world a better place.

Members of the group have very different skill sets. Some are extremely good at using numerical methods to model solar cells, others have a strong background in traditional materials science and others excel at building and using complex lab equipment.

6. Will contacting professors before applying to Stanford increase my chances of being admitted? Can you look over my credentials and let me know what my chances of being admitted are?

Unfortunately since hundreds of students contact each professor every year, most professors do not have time to read through the emails. The emails will have no impact on whether or not you get admitted. The best way to get into Stanford is simply to build up the best set of credentials you can and carefully fill out the application. Most professors do not think about who should be admitted until all of the files are in and the admissions committee is getting ready to meet.

If you have been admitted to Stanford and are interested in joining the group, you definitely should contact professor McGehee and set up an appointment to talk on the phone or visit Stanford.

7. Where do students go after they finish?

Most students have gone to work for Silicon Valley startup companies. A few have gone to large companies like DuPont or the consulting firm McKinsey. One student went to NIST and won the Presidential Early Career Award. Eight students and post docs from the group cofounded six companies (Allion, Dragonfly Systems, NextTint, PLANT PV, Sinovia and Thin Silicon) right after leaving Stanford. Two group members have received the Forbes 30 under 30 Award. Although most members of the group have not been able to resist the temptation to start up a company, we are open to training future professors. Two post docs from the group are now teaching at AMOLF and Kentucky.