Abnormal behaviors in galvanically displaced Au nanostructure on silicon below and above percolation threshold a coverage of Au nanostructure.

Temperature dependent resistivity of galvanically displaced Au nanostructure (NS) on $p$-type Silicon ($p$-Si) was investigated by tuning a coverage of Au NS below and above a percolation threshold ($p_{c})$ in temperature range of 10-300K. Below $p_{c}$ [Au nanoparticles are deposited on $p$-Si], the temperature coefficient of resistivity (TCR) and cryogenic sensitivity (S$_{\mathrm{v}})$ of $p$-Si in the low-temperature region (10--30 K) are remarkably improved upto 35{\%} of TCR and 5785{\%} of S$_{\mathrm{v}}$ in Au coverage of 21.9{\%} compared to $p$-Si. Above $p_{c}$ [Au nanofeatures (NFs) are deposited on $p$-Si], the resistivity of the Au NFs on $p$-Si show metal to semiconductor transition (MST) as the temperature increases and the temperature of the MST is tuned from 145 to 232 K as Au{\%} is changed from 82.7 to 54.3{\%}. Our investigation can propose a new optoelectronic application by galvanic displacement method and can provide the better understanding for effect of metal NS on doped semiconductor in the galvanic displacement method.