Berlin 2015 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

O: Fachverband Oberflächenphysik

O 38: Semiconductor Substrates

O 38.7: Poster

Tuesday, March 17, 2015, 18:15–21:00, Poster A

Surface Analysis of MOVPE-prepared GaP(111)B — •Peter Kleinschmidt¹, Pingo Mutombo², Oleksandr Romanyuk², Marcel Himmerlich³, Weihong Zhao¹, Andreas Nägelein¹, Matthias Steidl¹, Agnieszka Paszuk¹, Sebastian Brückner¹, Oliver Supplie¹, Stefan Krischok³, and Thomas Hannappel¹ — ¹Photovoltaics Group, Institute of Physics, Technische Universität Ilmenau, 98684 Ilmenau, Germany — ²Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 00 Prague 6, Czech Republic — ³Technical Physics I, Institute of Physics, Technische Universität Ilmenau, 98684 Ilmenau, Germany

We have investigated the MOVPE-prepared GaP(111)B surface by LEED, XPS, and STM as well as ab intio DFT. We obtained atomically resolved occupied-state STM images, characterized by large, atomically flat terraces. Most areas on these terraces exhibit no discernable order, in agreement with the (1×1) LEED pattern we obtained. However, locally, the STM images also show (√3×√3) and c(2×4) ordering. Our measurements indicate P-induced surface states. The different surface reconstructions were analyzed by ab initio DFT and relative surface formation energies of the Ga-rich and P-rich structures were derived. The most energetically favorable structures were used for STM image simulations and compared with the experimental STM images.