Advanced Functional Materials

3D Crack-free colloidal assembly onto soft hydrophobic surface via the lift-up method is demonstrated. A surface relief structure on a PDMS substrate enables the formation of colloidal crystal assemblies that cannot be achieved on a plane PDMS substrate owing to the hydrophobic nature of its surface. Different relief patterns (cylindrical, cross-shaped, and long rectangular) and different sizes of uniform silica particles from 190 to 300 nm are investigated.

The charge transport in P3HT:PCBM bulk heterojunction solar cells in conventional and inverted device structures is investigated by surface potential measurements via scanning Kelvin probe microscopy. The cross-section of solar cells is accessed by milling holes with a focused ion beam, which enables the direct scan along the charge transport path.

The complex correlation between the structure of oxygen deficient spinel LiNi_0.5Mn_1.5O_4-δ and its ion and electron transport properties is revealed through first principles simulations. It is shown that neutral oxygen vacancies promote cation disorder leading to the creation of deep and shallow Mn³⁺ states, responsible for high and low voltage regions on the voltage–capacity curves.

Reported measurements of the anisotropy in the conductivity of spin coated films of PEDOT:PSS vary widely. A systematic study of the out-of-plane charge transport in thin films of PEDOT:PSS with varying PSS content is presented. It is suggested that the orders of magnitude change in anisotropy can be quantitatively explained on the basis of a percolating cluster model.

In-plane conductivity in PEDOT:PSS takes place via filaments. This conclusion is based on charge transport measurements that indicate quasi-one dimensional variable range hopping and is supported by transmission electron microscopy. At higher PEDOT to PSS ratios the number of connected filaments drastically increases, causing an orders of magnitude increase in conductivity, in good agreement with percolation theory.