Measurement of the specific heat and determination of the thermodynamic functions of relaxed amorphous silicon

Abstract

The specific heat, c p , of two amorphous silicon (a-Si) samples has been measured by differential scanning calorimetry in the 100-900 K temperature range. When the hydrogen content is reduced by thermal annealing, c p approaches the value of crystalline Si (c-Si). Within experimental accuracy, we conclude that c p of relaxed pure a-Si coincides with that of c-Si. This result is used to determine the enthalpy, entropy, and Gibbs free energy of defect-free relaxed a-Si. Finally, the contribution of structural defects on these quantities is calculated and the melting point of several states of a-Si is predicted. V C 2013 AIP Publishing LLC. [http://dx

In situ observation of droplet nanofluidics for yielding low-dimensional nanomaterials

“…Furthermore, Equation ( 3) also brings insights to the zigzag growth of IPSLS Si (or Ge) nanowires catalyzed by Sn droplets [47,48]. Due to the higher equilibrium concentration (i.e.…”

“…Furthermore, a continuous NW growth led by a crawling droplet is mainly enabled by three cyclic events as seen in Figure4b: (i) In droplet reactively wets a-Si:H based on a solidliquid-solid process where liquid In alloys with Si atoms by dissolving a-Si:H until Si supersaturation, which thereafter activates heterogeneous nucleation and c-Si growth. Such process is driven by the Gibbs free energy difference between a-Si:H and c-Si;[48] (ii) consequently, a wettability gradient is established, from the non-reactive bare substrate (i.e.…”