Actually, I had a funny-bad experience in my first week living in Berlin. On that day, I just wanted to survey “how to reach HZB from apartment”. I was accompanied by my mom and dad. We bought single trip ABC ticket from Jungfernheide (near Charlottenburg) station since we hadn’t known yet about the zone. The outbound journey was fine, we took S41 then S7 to Wannsee and 318 bus. There was also a ticket checker but we passed it.   When we did the return journey, we got some problems. At first, the ticket machine couldn’t be changed into English version. Our phone were alsoRead More →

Ingredients: kesterite bulks, carbon boats, liquid nitrogen, quartz ampoule Hi everybody today we are going to prepare one of my favorite “dishes”- Homogeneous kesterite. But first of all, put on gloves and lab coats to protect yourself from accidents. Preparation can be divided in the following steps: 1.Grinding Put kesterite bulks in an agate mortar and grind them using a pestle until you obtain a homogenous mass (powder). Imagine that you are making mashed potatoes. 2.Pressing pellets Use a hydraulic press to turn your powders into cylindrical pellets. To do this, fill the pressing tool with the powder and press it for 5 minutes. WhenRead More →

In order to make use of the current produced in a solar cell, one needs electrodes and cables to transport the produced charge carriers to the consumer – but how do the charge carriers reach the electrodes? In many solar cell types, a conductive material is necessary. As the sunlight still needs to reach the absorber layer (where the energy-transfer from photons to electrons and thus the generation of the charge carriers happens), this material not just needs to be conductive but also transparent in a wide wavelength range. This difficult task is taken over by Transparent Conductive Oxides (TCOs). Metal oxides have shown toRead More →

Behind The Camera Berlin!!! I haven’t ever thought of coming to Berlin. It is actually like a dream for every people in our country. I live in a country named Bangladesh where people struggle every day to meet their fundamental rights such as food, education, health, etc. Our country has a lot of people compare to the area of her. So it is natural that she doesn’t have that much quality educational institution for pursuing higher education. Every year a lot of people compete to get into the public university but only a few can make it. Considering all these struggles and scenarios, it isRead More →

I want you to imagine the sun with wrong rays that cause a lot of problems. We cannot enjoy the sunshine. We want to do something to replace the wrong rays with the right ones. In my scientific project, the sun is germanium (Ge) nanoparticles, and the rays are a ligand. The wrong ligand is oleylamine. Oleylamine is an organic molecule containing an amino group and a long hydrocarbon chain. It would be perfect to remove oleylamine from the particles and attach another molecule. Speaking in scientific language, I am trying to do ligand exchange on germanium nanoparticles surface. Why germanium? Firstly, Ge is anRead More →

quantum dot picture

If you imagine an atom being of the size of a cherry then a quantum dot (QD) is a watermelon. Although it is much bigger than an atom, a QD is still a small object, nanometers long, and it preserves atomic features. One of them is a discrete energy spectrum. For this reason, many people address QDs as „artificial atoms“.

The great thing about QDs is that …Read More →