Three main reasons for a temperature increase in activated p-InAsSbP/n-InAs/n-InAsSbP and p-InAsSbP/ n-InAsSb/n-InAs double heterostructures has been considered, contribution of nonradiative Auger recombination, electron-phonon interaction and Joule heating to diode temperature increase in single element LEDs and flip-chip diode arrays (1x3) were evaluated at forward and reverse bias using data on spatial distribution of the mid-IR radiation intensity and current-voltage characteristics. Keywords: IR LED, IR diode array, Joule heating, Auger recombination, electron-phonon interaction.
We discuss photoelectrical properties of an on-chip attenuated total reflection (ATR) sensor for the ethanol concentration measurements in an aqueous solution. The on-chip sensor/microchip was made from a p-InAsSbP/n-InAs monolithic double heterostructure with three mesas/individual diodes grown on a single n+-InAs substrate/waveguide. Two heterostructure diodes were used as photodiodes, while the third one - as a LED. The ethanol concentration was measured via an algorithm based on analysis of the I-V characteristic parameters of a photodiode and the L-I characteristics of the LED. Keywords: photodiodes in the mid-IR range, LEDs in the mid-IR range, on-chip sensor, optical sensors, ATR sensor.
This paper focuses on the specific features of an Ohmic contact on undoped n-InAs (n = 2 x 1016 cm-3) that could be used for temperature stabilization and/or temperature reduction in electronic devices, mainly operating in the 3-5 mu m mid-IR range. This feature has been demonstrated in a 100 mu m thick n-InAs slab with three unannealed Cr-Au-Ni-Au contacts formed via evaporation in vacuum. The I-V characteristics showed no deviation from Ohm's law in the temperature range 77-340 K, manifesting a contact resistance ranging from 3.6 x 10-5 to 7.2 x 10-5 Omega cm2 at room temperature. The 2D thermal radiation distribution and the temperature distribution over the n-InAs surface opposite the contact side surface was obtained via a pre-calibrated IR microscope operating at a wavelength of 3 mu m. The measurements revealed a current dependent temperature decline in the area adjacent to the negatively biased contact: at the applied power of 5 mW, cooling as strong as Delta T approximate to 1 K occurred at an ambient temperature of 340 K. The results show potential for the fabrication of heterostructures with a "built-in" cooler that is monolithically integrated with another electronic device.
2D thermal radiation distribution together with I-V and L-I characteristics has been measured and analyzed in forward and reverse biased p-n heterostructures based on InAs0.9Sb0.1 and grown onto n-InAs substrates. The measurements revealed a sufficient difference in the temperature distribution onto the sample surface at forward and reverse bias, which is explained by an impact of heat pump operation initiated by an electron-phonon interaction at the p-n junction and diode contacts at U < 0.
Three main reasons for a temperature increase in activated p-InAsSbP/n-InAs/n-InAsSbP and p-InAsSbP/n-InAsSb/n-InAs double heterostructures has been considered. Contribution of nonradiative Auger recombination, electron-phonon interaction and Joule heating to diode temperature increase in single element LEDs and flip-chip diode arrays (1×3) were evaluated at forward and reverse bias using data on spatial distribution of the mid-IR radiation intensity and current-voltage characteristics.
We study the low frequency noise in infra-red InAs photodiodes (PDs) in the frequency range 1 – 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> Hz at room and cryogenic temperatures. We compare noise characteristics of two types of photodiodes: Single Heterostructure PDs and Double Heterostructure PDs and demonstrate the advantages of Double Heterostructure technology. We find that for comparable size, composition, and thickness of the photosensitive layers, the current noise in Double Heterostructure PD is significantly lower than in Single Heterostructure PD at both room and cryogenic temperatures. In addition, we measure the optical output noise in InAsSbP/InAs LEDs at 300K and find that its intensity is less than the intensity of the photodiode reverse bias current noise by ~4 orders of magnitude.
We discuss photoelectrical properties of an on-chip attenuated total reflection (ATR) sensor for the ethanol concentration measurements in an aqueous solution. The on-chip sensor/microchip was made from a p-InAsSbP/n-InAs monolithic double heterostructure with three mesas/individual diodes grown on a single n⁺-InAs substrate/waveguide. Two heterostructure diodes were used as photodiodes, while the third one - as a LED. The ethanol concentration was measured via an algorithm based on analysis of the I–V characteristic parameters of a photodiode and the L–I characteristics of an LED.
I–V and L–I characteristics as well as photocurrent in monolithic p‐InAsSbP/n‐InAs double heterostructure (λ = 3.4 μm) with several mesas/individual diodes grown onto a single n + ‐InAs substrate have been measured at an activation of one of the diodes at ambient temperature in the presence of water, ethanol, and H 2 0 + C 2 H 5 OH mixture at the n + ‐InAs substrate surface. Adequately sufficient photocurrent values, the evidence for the absorption of internally reflected infrared radiation at the n + ‐InAs substrate/liquid interface together with the correlation between the photocurrent and liquid chemical composition indicate the possibility of developing p‐InAsSbP/n‐InAs double heterostructures into a miniature monolithic “on‐chip” evanescent wave sensor of different liquids.
The frequency and current dependences of the optical output spectral noise density, Slph, in p-InAsSbP/n-InAs infrared light emitting diodes (LEDs) has been measured for the first time. LEDs with emission centered at wavelengths lambda = 2.8 and 3.5 mu m have been studied. In both cases, in the frequency range 2 <= f <= 100 Hz the noise spectrum is 1/f like. At constant LED pumping current, Slph is proportional to the photocurrent squared (-Iph2). The 1/f noise intensity Slph for the LED with emission centered at lambda = 2.8 mu m is -2 times higher. In the LED pumping current range 0.02 <= ILED <= 0.1 A (60 <= jLED <= 300 A/cm2) the optical output 1/f noise is practically independent of ILED.The intensity of the LEDs' optical output 1/f noise is less than the intensity of the photodiode reverse bias current noise by -4 orders of magnitude.
Low frequency noise in P-InAsSbP/n-InAs infrared light emitting diode- photodiode pairs is investigated for the first time at 300 K. It is shown that photocurrent fluctuations under LED illumination are smaller than photocurrent fluctuations under a black body illumination. When the photodiode is illuminated by LED, the spectral noise density follows the 1/f dependence. In the case of a black body illumination we observe a significant contribution of generation-recombination noise.
The current–voltage characteristics and photocurrent of “monolithic” diode optical pairs optically coupled by a substrate made of InAs common for them are considered, and the possibility of using the values of the photocurrent for measuring the attenuation of the “evanescent wave” in the case of total internal reflectance in the waveguide (a substrate made of InAs)/absorbing substance under analysis interphase boundary is evaluated.
Low frequency photocurrent noise, as well as the forward current noise are studied for the first time in mid infrared InAsSbP/InAs double heterostructure photodiodes at 100 K. Two types of photodiodes are identified. For the first type, the spectral noise density, SI, depends on frequency as 1/f(gamma). For the second type, generation recombination (GR) noise component dominates. Our results show that in those samples, it is one and the same local center that is responsible for the noise over the entire photocurrent range. The forward current noise in all samples is lower than that previously observed in InAsSbP/InAs single heterostructure photodiodes at 77 K. In samples demonstrating 1/f gamma noise, the spectral noise density, S-I, is proportional to the square of the current. In samples with GR noise, we also observe S-I similar to I-2 dependences in a certain current range. At higher currents, the noise decreases or tends to saturate. We show that at 100 K, the Nyquist noise is dominant and can be used for estimating the specific detectivity at photocurrents Iph < 5.10(-9) A for samples showing 1/f(gamma). noise, and at Iph < 2.10(-9) A for samples presenting GR noise component. At higher Iph the photocurrent noise should be also taken into account.
Low frequency reverse current noise is studied for the first time in InAsSbP/InAs double heterostructure (DH) photodiodes in the frequency range 1 Hz-10(4) Hz at 300 K and 100 K. At room temperature, the noise in the DH photodiodes is 1/f and might be significantly lower (by similar to 17 dB) than in single heterostructure InAsSbP/InAs photodiodes. In the practically most important regime of low reverse currents, I-rb, the current dependence of spectral noise density is proportional to I-rb(2), both at 300 K and 100 K. The reverse current noise might provide the limit for the detectivity of DH photodiodes at I-rb > 3 x 10(-6) A at 300 K and I-rb > 8 x 10(-9) A at 100 K.
AbstractThe results of investigations of light-emitting diodes based on heterostructures with an InAs active region grown by liquid phase and metalorganic vapor-phase epitaxy over the last decade are reviewed. The near-field pattern, L – I and I – V characteristics, and quantum efficiency of point-contact and flip-chip light-emitting diodes are analyzed in a wide temperature range.
The results of investigations of light-emitting diodes based on heterostructures with an InAs active region grown by liquid phase and metalorganic vapor-phase epitaxy over the last decade are reviewed. The near-field pattern, L–I and I–V characteristics, and quantum efficiency of point-contact and flip-chip light-emitting diodes are analyzed in a wide temperature range.
N- InAsSbP/InAs /P- InAsSbP double heterostructures have been grown onto n + -InAs substrate and further processed into 2×2 photodiode array containing no n + - InAs. C-V, spectral response as well as mid-IR photoluminescence and electroluminescence in the 77-300 K temperature range have been measured and used for photodiode characterization including D*(λ) and BLIP temperature evaluation.
•Linear impurity distribution near the p-n junction.•Low unit area capacity (Co/A)77 K = 4.3 × 10−8 F × cm−2).•D4.7μm,300K∗ as high as 6.5 × 108 Jones.
Research data for photovoltaic, I–V, and C–V characteristics of InAsSbP/InAs heterostructure photodiodes that operate at room temperature in the wavelength range 2.6–2.8 μm have been reported. Based on these data and available publications, conclusions have been drawn about the prospects for using these photodiodes in a number of applications.
Current–voltage and photoelectrical characteristics of InAs0.7Sb0.3 photodiodes grown onto InAs substrates are investigated in the interval of 212–330 K, i.e., the “thermoelectrical temperature range”. The impacts of mesa diameter, buffer layer thickness, and cooling on the zero‐bias resistance and spectral responsivity are described and analyzed. At low temperatures, the dynamic zero‐bias resistance dominat the serial one, resulting in the specific detectivity at 6.5 µm and at T = 233 K being as high as 3.2 · 108 cm Hz1/2 W−1 for a flat‐plate photodiode.