Study on the temperature sensing capability of a light-emitting diode

Abstract

A study on the temperature sensing capability of a light-emitting diode ͑LED͒ has been made. Dependence of I-V characteristics as a function of temperature is used as a temperature sensing mechanism. It is found that the temperature voltage characteristics of a GaP LED are quite linear from 77 to 533 K. The measured sensitivity of the diode is 5.31 mV/K at 1 pA and is 2.34 mV/K at 0.1 mA. Since the reverse saturation current of LED is less than fempto-ampere range, it is possible to operate the thermometer at low currents, as compared to silicon or germanium diode thermometers, which reduce power dissipation in the device. It has been possible to extend the temperature range to higher value due to large value of band gap for LEDs.

Temperature dependence of the lifetime of nonequilibrium charge carriers in GaP diodes under condition of recombination current domination

“…They madẽ 1.5 in our case and~2.5 in the Ref. [4]. In our opinion this might be the indirect proof of similarity of recombination processes in different GaP diodes based on p þ -n-type junction.…”

“…In particular, extrapolation of both dependencies (ours and the one from ref. [4]) up to 1000/T/0 allowed us to obtain close values of log I 0 * . They madẽ 1.5 in our case and~2.5 in the Ref.…”

“…3 of Ref. [4] obtained for commercial GaP light-emitting diodes (LED). In particular, extrapolation of both dependencies (ours and the one from ref.…”

“…This is in agreement with Eqs. (2) and (4). We note that the degree of such an influence is quite limited in our 1 The value was refined later using 1/C 2 ¼ f(U) curves of the finished diodes.…”

“…The devices mentioned are primarily extreme electronic devices [2] as well as hightemperature diode thermometers [3]. The latter case had shown [4] that operation of a diode thermometer at low (recombination) current improved the linearity of its temperature response characteristic (TRC) did not "overheat" the crystal and allowed to build micro-or nanowatt power consumption thermometers.…”