Identification of Current Transport Mechanisms and Temperature Sensing Qualifications for Al/(ZnS-PVA)/p-Si Structures at Low and Moderate Temperatures
A. Arslan Alsaç, Tülay Seri̇n, Serhat Orkun Tan, Ş. Altındal
Abstract
Current transport mechanisms (CTMs) and temperature sensing qualifications of Al/(ZnS-PVA)/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${p}$ </tex-math></inline-formula> -Si structures are identified with the help of temperature-dependent forward bias current-voltage measurements. To determine the current transport mechanism, the electrical parameters of the structure such as saturation current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{o}$ </tex-math></inline-formula> ), zero – bias barrier height ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Phi _{B0}$ </tex-math></inline-formula> ), ideality factor ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> ) are determined from these characteristics measured in the temperature range of 60–320 K. The temperature dependencies of the calculated <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Phi _{\textit {Bo}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> values indicate the existence of double Gaussian distribution (DGD) of barrier height (BH) at M/S interface. Using the modified Richardson plots, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Phi _{B0}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}^{\ast }$ </tex-math></inline-formula> values have been found in the high temperature region (HT) (160-320 K) as 0.95 eV, 31.64 A.cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> , respectively and in the low temperature region (60-140 K) as 0.3871 eV, 20.996 A.cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> , respectively. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}^\ast $ </tex-math></inline-formula> value in the HT region is very close to its theoretical value and hence the CTMs can be explained by the DGD of BH. Sensitivity ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${S}$ </tex-math></inline-formula> ) values are calculated for each voltage at forward biases from the temperature-dependent variation of the logarithm of the current ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">InI</i> ). A peak value of 7.5 mA/K at 0.5 V was obtained for the sensor with a good linear characteristic and high sensitivity. The results clearly show that the structure can be used successfully and properly as a temperature sensor.