On the investigation of current transport mechanisms (CTMs) of the crystalline Si solar cells utilizing current/voltage (I-V) characteristics in temperature range of 110-380 K

In this study, crystalline-silicon (Si) solar cells (SCs) were manufactured and their possible current transport/conduction mechanisms (CTMs) were investigated in depth using current-voltage-temperature (I-V-T) measurements in the temperature range of 110-380 K to get more accurate results on the possible CTMs and temperature dependence on the key electrical parameters. While the value of zero-bias barrier height (Phi B0) increases with temperature, the ideality factor (n) decreases. Additionally, the conventional Richardson plot deviated from the linearity at low temperatures and calculated Richardson constant (A* = 1.73 x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document} 10-6A/(cm.K)2) is 1.85 x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document} 107 times higher than its theoretical value (32 A/(cm.K)2). These results show a deviation from the standard thermionic-emission (TE) theory. The obtained positive temperature coefficient (alpha = d Phi B0/dT) is in agreement with the negative temperature coefficient of the bandgap of the ideal Schottky diode/SC. Therefore, the Phi B0-q/2kT, Phi B0-n, and nkT/q vs kT/q plots were drawn to determine possible CTMs like tunneling (thermionic field/field emission; TFE/FE) and Gaussian distribution (GD) of barrier heights (BHs). The interface states (Nss) versus Ess-Ev profile were drawn for each temperature by considering the voltage dependence of BH and n. The average value of PhiB0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\overline{\Phi }_{{{\text{B0}}}}$$\end{document}B0 and standard deviation (sigma s) were calculated from the intercept and slope of the Phi B0-q/2kT plot as 1.1587 eV and 0.1187 V, respectively. After that, values of both PhiB0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\overline{\Phi }_{{{\text{B0}}}}$$\end{document} and A* were calculated from the slope and intercept of the modified Richardson plot as 1.07 eV and 31.67 A/(cmK)2, respectively. These values are very close to the BH at 0 K (1.17 eV) and the theoretical value of A* (32 A/(cmK)2). Therefore, the CTMs of the SC were successfully explained through the TE model with a GD of BHs rather than the other CTMs.