Magnetic field control of charge transport in solar cells and mechanically controlled break junction devices

Controlling the electronic transport through solid state devices has been of utmost importance to develop high efficient devices for practical applications like energy conversion, data storage, sensing applications etc. In this context, the charge transport can be broadly classified into two categories – (a) Diffusive and (b) Ballistic transport. In the Diffusive regime, electron mean free path is smaller than the length of the system and its width is larger than the Fermi wavelength (λF). In this case, electron transport is dominated by a series of scattering events which are mainly due to impurities and electron - phonon interactions. In the case of Ballistic regime, electron mean free path is greater than the length of the system and the width is comparable to λF. Ballistic transport theory describes the conduction through single atomic junctions. In this thesis, we have used the magnetic field as additional degree of freedom to control the transport phenomena in both diffusive and ballistic regimes. Essentially, magnetic field effect on (a) dye sensitized solar cells (Diffusive regime) and (b) mechanically controlled break junction devices (Ballistic regime) is explored.