000229933 001__ 229933
000229933 005__ 20180501105446.0
000229933 0247_ $$2doi$$a10.5075/epfl-thesis-7749
000229933 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis7749-5
000229933 02471 $$2nebis$$a10951278
000229933 037__ $$aTHESIS_LIB
000229933 041__ $$aeng
000229933 088__ $$a7749
000229933 245__ $$aInvestigations on hybrid organic-inorganic perovskites for high performance solar cells
000229933 260__ $$aLausanne$$bEPFL$$c2017
000229933 269__ $$a2017
000229933 336__ $$aTheses
000229933 502__ $$aProf. Ulf Anders Hagfeldt (président) ; Prof. Michael Graetzel, Prof. Joachim Maier (directeurs) ; Prof. Christophe Ballif, Prof. Aldo Di Carlo, Prof. Tomas Edvinsson (rapporteurs)
000229933 520__ $$aUndoubtedly, perovskite solar cells have become a key player in 3rd generation photovoltaics over the last few years. Although it is only in 2012 that the first solid state perovskite solar cell was reported, power conversion efficiencies have increased so rapidly that PSCs are now serious contenders to the well-established and marketed thin-film and wafer technologies. Over the timespan on this work, over 3€™000 published articles in peer-review journals have been published. The work that I report in this thesis is merely a small contribution to the gigantic amount of data, models and theories that have been made over the last 4 years. I hope that my modest contribution will be of value to the scientific community.  Over the course of this work, I attempted not to focus my attention on a single issue that relates to perovskite photovoltaics, but to approach it from different perspectives. As a result, a wide array of subjects have been treated.  Starting with the fabrication of perovskite solar cells, an innovative way to deposit thin film of perovskite from solution is reported, using a two-step deposition technique. Using this approach, the power conversion efficiency of perovskite solar cells has been increased from 12.3% to over 17% in less than a year.  Subsequently, I looked into the possible compositional variations of the perovskite layer. This study showed that the cation methylammonium and formamidinium can be used inter- changeably using the deposition technique that we have reported on earlier. We showed that a mixture of the two cations leads to a stabilization of the tetragonal perovskite phase and shrinks the optical band gap of the photoabsorber, allowing more photons to be absorbed and converted into electrons.  Following this work, I studied some of the reactivity properties of the phase pure organic inorganic CH3NH3PbX3(X=Cl,Br,I). Notably, it could be shown that the halide component can be easily exchanged by another one from a simple solution based anion exchange reaction.  Later, the power conversion characteristics of perovskite solar cells were investigated. By developing a electronic circuit allowing versatile power point tracking of the solar cells, a new algorithm that deals with the issues specifically related to perovskite solar cells is reported.  i   A major topic of my work was the study of the frequency resolved dynamics that results for the generation carriers by light. Using a novel way to measure the intensity modulated spectral response of perovskite solar cells, I was able to identify some of the key limiting factors that cap the power conversion efficiency of the devices. A numerical model that answers to the laws of carrier dynamics was assembled and used as a tool to better understand perovskite solar cells.  Finally, I reported on a way to deal with the end of life of perovskite solar cells. Some of the relevant regulatory framework in the European Union that deals with the recycling of solar panels are highlighted. Using the concept of "upcycling", a way to recycle the valuable components of the solar cell in an efficient way was outlined.
000229933 6531_ $$aPhotovoltaics
000229933 6531_ $$aSolar Cells
000229933 6531_ $$aPerovskite
000229933 6531_ $$aHybrid Organic Inorganic Perovskite
000229933 6531_ $$aMesoscopic
000229933 6531_ $$aMaximum power point tracking
000229933 700__ $$0247078$$aPellet, Norman$$g179666
000229933 720_2 $$0240191$$aGraetzel, Michael$$edir.$$g105292
000229933 720_2 $$0(EPFLAUTH)235296$$aMaier, Joachim$$edir.$$g235296
000229933 8564_ $$s32478091$$uhttps://infoscience.epfl.ch/record/229933/files/EPFL_TH7749.pdf$$yn/a$$zn/a
000229933 909C0 $$0252060$$pLPI$$xU10101
000229933 909CO $$ooai:infoscience.tind.io:229933$$pSB$$pthesis-bn2018$$pDOI2$$pDOI$$pthesis
000229933 917Z8 $$x108898
000229933 917Z8 $$x108898
000229933 918__ $$aSB$$cISIC$$dEDCH
000229933 919__ $$aLPI
000229933 920__ $$a2017-7-21$$b2017
000229933 970__ $$a7749/THESES
000229933 973__ $$aEPFL$$sPUBLISHED
000229933 980__ $$aTHESIS