Fluctuation model for p–n heterojunction solar cells

Diffused p‐n GaAs junctions with nano/microrelief active interface

“…The preliminary slight etching of n-GaAs in polishing etchant or removing oxide layer in HCl solution result in roughly the same photoelectric characteristics of structures with diffused p + -n junction. To explain less value of V oc for the structures with more developed microrelief the fluctuation model for the average oc V was elaborated taking into account lateral fluctuation of doping impurity concentration and different components of the current flow (the diffusion, recombination and tunnel components) [3]. The comparative study of the mechanisms of the current flow in p + -n-junctions with flat and microrelief interfaces was made by measurement and analysis of their dark current-voltage dependencies in the 80-360 K temperature range.…”

“…1 Introduction Using of non-flat (micro/nanorelief, texturized, porous) surfaces of semiconductor compounds has several important aspects, such as: i) physical-chemical aspect of growth of single crystals on the so-called soft substrate with non-matching lattice constants [1]; ii) promising method to reduce optical losses related to light reflection, and to increase the photoelectric devices efficiency [2]; iii) as an active interface with potential barrier separating the electron-hole pairs (p-n junction, heterojunction) [3]; iv) as some matching layer for excitation of surface polaritons (particularly plasmons) which is not possible on flat surface; v) as a template for deposition of nanoparticles or their ensembles of conducting materials (especially metals) for aims of plasmonics [4]. This report is devoted to elaboration of technology of a submicron p + -GaAs layer formation on nano/microtextured n-GaAs substrate, characterization of these p-n junctions by atomic force microscopy (AFM), optical and electric methods, and application of them for photodetectors and solar cells.…”

Efficiency enhancement of surface barrier solar cells due to excitation of surface plasmon polaritons

“…To estimate the V OC value in the case of a non-flat interface of SBH, we used the results of [7,8] for a randomly rough MS interface. Therefore, V OC has been obtained by the following expression:…”

“…• In thin film SCs, the subwavelength scatterers can couple sunlight into guided modes in the semiconductor layer, when the back interface is coated with a corrugated metal film [5,6]; this shows the design of ultrathin SCs that exhibit enhanced absorption. • The light scattering from metal nanoparticles near their local (surface) plasmons (SPs) excitation is also a promising way to increase the light absorption [7,8] in thin film SCs or the enhancement of electroluminescence in thin Si-on-insulator light-emitting diodes [12]. Two basic mechanisms have been proposed to explain photocurrent enhancement by metal nanoparticles incorporated into SC: light scattering and near-field concentration of light.…”

“…Due to enhancement of the light transmittance to the absorptive layer of SBH with periodical microrelief, the shortcircuit photocurrent J SC increases, but at the same time both the lateral inhomogeneity of the emitter layer and the increase of its area can lead to the decrease of the open-circuit voltage V OC [7,8], since the surface recombination rate increases. Moreover, the short-circuit photocurrent can change with increasing the interface area and the related increasing of the surface recombination rate as well as rates of other interface electron/hole transitions.…”