Simulation of the growth dynamics of amorphous and microcrystalline silicon

Abstract

The qualitative description of the major microstructure characteristics of microcrystalline silicon is achieved through a threedimensional discrete dynamical growth model. The model is based on three fundamental processes that determine surface morphology: (1) random deposition of particles, (2) local relaxation and (3) desorption. In this model, the incoming particle reaching the growing surface takes on a state variable representing a particular way of being incorporated into the material. The state variable is attributed according to a simple selection rule that is characteristic of the model. This model reproduces most of the features of the complex microstructure of microcrystalline silicon: transition from amorphous to crystalline phase, conical shape of the crystalline domains, crystalline fraction evolution with respect to the layer thickness and roughness evolution versus layer thickness.

P‐6: Top‐Gate and Bottom‐Gate Amorphous ZnO Transparent TFTs Fabricated by All‐Etching Processes

“…All these results indicate the manifestation of phase transition from amorphous to polycrystalline structure with increasing ZnO film thickness. Studies on similar thickness dependent crystallinity of various materials have also been reported by researchers [13][14][15]. In the initial stage of the film growth, only very few and small nanocrystallitic islands may exist in the film (thus should be considered as amorphous film).…”

Phase diagram and microstructure of microcrystalline and amorphous silicon: a numerical growth simulation

“…Note that the number of states n used for representing the different crystallographic orientations must be at any rate higher than 10 according to crystallographic considerations exposed in [6]. The first condition is fulfilled with all points of the phase diagram except the two regions defined by n<5 and t<4 for which the crystalline fraction is high even without any etching.…”

“…Details are given in [6]; the main simulation steps are summarized here. Random deposition and relaxation: A cubic particle is released from a position randomly chosen above the layer surface.…”

“…The minimum number of states, typically higher than 10, used to render the crystallographic orientations in silicon is discussed in [6]. A crystalline region is thus defined as a domain of the cubic lattice filled with particles of the same color.…”

Coupling and Trapping of Light in Thin-Film Solar Cells Using Modulated Interface Textures

“…The texture of the back reflector in superstrate technology is mainly influenced by two factors: the front contact texture and the evolution of the growing absorber layer's surface. This modification is governed by a flattening of the rough interface and by the growth inherent texture of the absorber layers [21,[58][59][60]. Studies have shown that the growth of silicon is non-conformal [21,58,61].…”