With Europe being so far from North America and my country of origin I was expecting to do a lot of travel while in Switzerland and see as much of the country and continent as possible during my weekends. I knew that this would probably be quite tiring but it was the opportunity of a lifetime. I became slightly disappointed when I learned that traveling in Switzerland was indeed quite costly but my determination to get to know the area was still strong. From previous experiences in Switzerland I knew the weather to be agreeably warm and sunny during the summer and was glad that I would be getting a break from the Boston cold.
I was also excited and looking forward to working in a field that I was truly interested in. Despite the fact that I had preferred industry during my internship search but had actually ended up in a research internship, there was a very short path between the research being done at the lab where I would intern and its implementation in industry for real-world consumer products.
During my internship I worked with lead halide perovskite solar cells, a solar cell technology that started growing in 2009. The perovskite material, CH3NH3PbX3 where X is I, Cl, or Br, has a cubic crystal structure with strong light absorption and a direct bandgap which is at around 1.55 eV for pure iodide perovskites. Most high-efficiency perovskite cells require high temperatures (500°C) to fabricate the needed TiO2 scaffolding. This technology is not yet used in industry but the research that I participated in was aimed at making this technology competitive with solar cell technologies that are currently in use by decreasing the temperature requirements of fabrication while keeping the efficiency high enough. Perovskites themselves show potential for the solar cell industry because they are cheaper and more easily fabricated than silicon cells.
In the first few weeks of my internship I focused on low-temperature perovskite cells, carrying out research to expand my knowledge of the subject I had never before dealt with as well as looking for and testing published methods that could be incorporated into the current procedure used in my lab. We made several runs to test multiple methods of making low-temperature, planar solar cells, as it is the TiO2 scaffolding that requires the high annealing temperatures that currently make this technology impractical. Decreasing the processing temperatures also allows for the possibility of making the cells on a greater variety of substrates, including flexible substrates.
I also studied the degradation and stability of the new material, as this too is a key aspect in allowing for the perovskite technology to be implemented in industry. Perovskite layers are traditionally very easily and quickly degraded in the presence of water. We experimented with mixed halide perovskites as the lab standard was a perovskite that used only iodide ions, but mixed halide perovskite layers, i.e. I3-XBrx, have been shown to be more stable. Several experiments were set up to vary the iodide to bromide ratios in the perovskite and the absorption, transmittance, and degradation of each type of layer were studied after they were kept under different conditions (inert atmosphere, exposure to light, dark, etc.). For this purpose, photothermal deflection spectroscopy (PDS) was employed, a highly sensitive method to detect material defects.
Neuchâtel – Switzerland
A small town on the shores of the biggest completely Swiss-owned lake in Switzerland, Neuchâtel was my home during my internship with EPFL. Despite its small population and small town feel there are a lot of things to do and see in the city. A trip downtown to see the Rue du Seyon and Rue des Moulins on my first weekend here immediately won my heart and I was sure I would be returning here often, whether it be to sit at a bar/restaurant, go shopping, or see the market on Tuesdays and Saturdays. While in the area I visited the Collegiale and the Chateau, from where the canton is still governed today – I enjoyed the views meant for kings, saw the ancient treasure room, took a place on the benches at the courthouse, and sat in the place of a journalist in the main conference room, built where the stables used to be.
Being in a small town allowed me to enjoy some truly legitimate Swiss culture, but the Swiss transportation system also allowed me to travel to other places around Switzerland with ease. I was able to visit friends in Geneva and Zürich as well as travel with interns from the Lausanne site to the Montreux Jazz Festival, the Gruyère cheese factory, and the Cailler chocolate factory at Broc, amongst other places. The landscapes in Switzerland are picturesque and no matter where you are travelling, this country really allows you to enjoy the trip and not just the destination as a simple glance out the train window will reveal rolling hills planted with grains, grapes, or sunflowers, mirror-like lakes, or post-card views of the Swiss Alps.
Montreux – Jazz Festival, Chateau de Chillon
In the middle of world cup season, this trip down to the Montreux Jazz Festival 2014 allowed me to experience one of the football games on a big screen with other interns from Lausanne, some Brazilian music, and a trip to the famously beautiful Chateau de Chillon in addition to the Jazz Festival. The Chateau was the biggest that I had seen in Switzerland so far and the feeling of it reminded me of some films and TV shows I had watched. Everything seemed very genuine despite the crowds of tourists and to make things even more interesting George RR Martin also visited the castle at the same time and we all got a picture with him at the end of our tour.
Enjoying the atmosphere of the festival was also fun and relaxing as we sat on the lawn near the lake or some lawn chairs and enjoyed the sounds of music, people, and the small souvenir market around us. I will definitely want to visit this festival and spend a little longer there at some point in the future.
Gruyère – Cheese Factory & Broc – Cailler Factory
What could possibly be more Swiss than cheese and chocolate? At the cheese and chocolate factories in the Gruyère area I had the opportunity to see and learn about the cheese and chocolate making process and even taste some of the final product. Around the small towns it is also possible to see the farms where the cows are raised. This trip was very enjoyable and allowed me to see and get to know a little piece of the Swiss culture and tradition of cheese and chocolate making. I learned that the Swiss people are one of the largest consumers of chocolate and after having been in Switzerland for a while I could understand why. Swiss chocolate is so amazing it is practically magical. One of the first times I went to the supermarket here in Switzerland I noticed that every single American Chocolate on the shelf was cheaper than even the cheapest Swiss chocolate and I laughed.
Geneva – August 9th Fireworks
Although the Swiss National Holiday is on August 1st, Geneva continues its partying in Fêtes de Geneve until August 9th when they close with a majestic firework display that is perfectly synchronized with music. I watch fireworks ever year on New Year`s Eve and have also been to a couple of July 4th celebrations in the USA but I can say with all honesty that the Fireworks in Geneva on August 9th were the best that I have ever seen. I watched them from the fourth floor of a building by the lake with some family friends and saw all of the CHF100 seats by the lake and on Mont Blanc Bridge and then all the remaining floor space on the bridge and between the buildings and the lake get completely occupied hours before the fireworks started.
Lucerne – Old town, Lake cruise, Mt. Pilatus
My trip to Lucerne was a spontaneous one but turned out unexpectedly considering this. I missed the train I meant to take and arrived only in the late morning and was immediately taken by the beautiful view of the lake. Having heard that The thing to do at Lucerne was to take a cruise on the lake the first thing I did was to check the cruise schedules. I decided I had enough time to walk around before taking the boat so I walked across the bridge and up the hill to the towers and wall reminiscent of castle defenses. After a short stroll through on the wall I went back down through the old town but the buildings and atmosphere so captured me that I arrived late at the docks and missed my boat too. Deciding to make the best of my situation I planned to take the next boat and to my surprise, after getting on the boat I discovered that I was going to be dropped off right next to the stop for the steepest cogwheel train in the world which climbs to the top of Mt. Pilatus.
I enjoyed the scenic boat ride with all the small farms and houses on the hills around the lake and then took the train up to Mt. Pilatus. From the top observatory all the fingers of Lake Lucerne could be seen and there was a full 360 view of all the land in the other directions too. I took a funicular and gondolas to descend the mountain on the side opposite from the one I had come up and only then did the sun, which had been shining all day in a blue sky, hide behind a cloud and let the rain take over. For an unplanned trip my day went extraordinarily well considering even the weather, which had been quite misbehaved all summer, was perfect.
Zermatt – Matterhorn
Having already visited Mt. Pilatus and having traveled through many other mountains in Switzerland did not prepare me for seeing the Matterhorn. I was expecting to arrive and be faced with a multitude of peaks amongst which I would have to search for the Matterhorn. I was thus awestruck when I looked up in the train to see a single peak rising above all the others in the area. It was undeniably the same peak I had seen countless times on Toblerone packaging, but more beautiful and bigger than I had ever imagined. We took a trip up to Sunnega in the funicular and were soon feeling the altitude as breathing became difficult more quickly than usual when we took a hike along the five-lake trail.
Jungfraujoch – Top of Europe
The Jungfraujoch is also called “The Top of Europe” and before going there I saw many reviews on travel sites saying that a visit here was a must if you are spending more than a week in Switzerland. I had only one weekend left in Switzerland and decided to go irrespective of non-ideal weather. Upon arrival at the station in Lauterbrunnen I headed over to the ticket office to buy my ticket and when the sbb worker told me the price I couldn`t believe him at first. The ticket was ridiculously expensive even for Swiss standards (CHF 88.10 for roundtrip with demi-tarif), but I decided that having already gone halfway there I had to make it to the top. I paid for my ticket and along with it I got a “passport” to prove that I had been to Jungfraujoch. As the train started to climb into the clouds visibility dropped to about 5m and all I could see was the were the Swiss Alpine flowers on one side of the tracks and on the other side, that of the cliff, there wasn`t even that much. At Kleine Scheidegg I changed over to a different train that would take me the rest of the way to the top. The train stopped at multiple viewing platforms along the way but all that could be seen out of the windows were clouds (there are also bathrooms at these viewing points and if you want to take a look out the viewing platform windows do it on the way up because the train does not stop there again on the way down).
Once we emerged out of the final tunnel and arrived at the highest station in Europe, however, the sun was out despite the below-freezing temperatures. I put on my second jacket and walked through the tour, going out onto the first viewing platform immediately in front of the station exit and walking through the chilly hallways and caves through the 360 panorama video room to arrive at the Sphinx. When I stepped out into the daylight with all the snow around me I realized that I should have brought sunglasses because the sunlight reflected off all the snow made it so that it took 5 minutes for my eyes to adjust so I could open them. Continuing my tour I went out to their snow fun area and found that to participate in any of the fun snow activities I needed to pay more. Instead, I decided to take the 45 minute walk up to the Mönchsjoch Hut. The sunlight outside made the air felt warmer than the one inside the caves and building and there is also a certain feeling of the Alps that just cannot be completely understood when you are standing behind a glass window. The climb actually took me about 1 hour including all the breaks for catching my breath and for picture-taking but the view was beautiful all along the way with the Jungfrau at my back, the Mönch in front of me, and the Aletsch glacier in the valley to my right. The monstrosity of the landscape around me was awe-inspiring. Once I reached the little hut cozy-ed up against the mountain and looked down the other side of the mountain I felt like I was standing on the edge of the world. The clouds below made it impossible to see the valley and I realized I was literally standing on a wonderland in the clouds. After returning into the observatory there was still the ice palace to see before returning and the ice sculptures were beautiful, but for me the edge of the world experience on the Mönch was unbeatable. At the end of the day I was very glad to have visited Jungfraujoch on my last weekend day in Switzerland and the trip was worth every one of the ridiculously many cents it cost me.
And finally, some last remarks
All in all I had a great time with MISTI Switzerland and the EPFL Research Internship Program, learning not only while I was in the lab, but also outside it. I ventured into an academic field that I had no previous experience with and a country I did not know well and as a result I gained both academic knowledge and knowledge about the world around me and myself.
I hope to continue developing my knowledge and experience in the field of renewable energy and use all that I have learned to further improve myself and give back to society.
Barbara Lima, Massachusetts Institute of Technology
Photovoltaics and Thin Film Electronics Laboratory PV-LAB, EPFL