High gain, low noise 1550  nm GaAsSb/AlGaAsSb avalanche photodiodes

Abstract

High sensitivity avalanche photodiodes (APDs) operating at eye-safe infrared wavelengths (1400–1650 nm) are essential components in many communications and sensing systems. We report the demonstration of a room temperature, ultrahigh gain ( M = 278 , λ = 1550 n m , V = 69.5 V , T = 296 K ) linear mode APD on an InP substrate using a G a A s 0.5 S b 0.5 / A l 0.85 G a 0.15 A s 0.56 S b 0.44 separate absorption, charge, and multiplication (SACM) heterostructure. This represents ∼ 10 × gain improvement ( M = 278 ) over commercial, state-of-the-art InGaAs/InP-based APDs ( M ∼ 30 ) operating at 1550 nm. The excess noise factor is extremely low ( F &lt;<!-- 3 ) at M = 70 , which is even lower than Si APDs. This design gives a quantum efficiency of 5935.3% at maximum gain. This SACM APD also shows an extremely low temperature breakdown sensitivity ( C b d ) of ∼ 11.83 m V / K , which is ∼ 10 × lower than equivalent InGaAs/InP commercial APDs. These major improvements in APD performance are likely to lead to their wide adoption in many photon-starved applications.

Non-Markovian Hole Excess Noise in Avalanche Amorphous Selenium Thin Films

“…The dashed lines represent the McIntyre history independent model, which has been successfully explained by the local-field theory of impact ionization. Circle markers show measured ENF results for GaAs, and square markers show measured ENF in InGaAs/InP APDs, , both matching the local-field theory McIntyre predictions corresponding to k ∼ 0.3 and k ∼ 0.5, respectively. Hexagon markers show noiseless avalanche gains of up to about eight achieved in a Capasso device using adequately designed heterojunctions with maximum gain stages, with J = 3 corresponding to a gain of eight .…”

“…History dependence can be introduced in the carrier branching process in APDs, thus increasing determinism, which further decreases the ENF below 2. ,,− After an ionization event occurs, each carrier needs to travel a minimum distance, which is frequently referred to as the “dead space/length,” before it can gain sufficient energy from the electric field to have a nonnegligible ionization probability. When the thickness of the multiplication region becomes comparable to a “few” dead spaces/lengths, the nonlocal/non-Markovian history-dependent effects dominate .…”

Investigation of recombination mechanisms in GaAsSb photodiodes using minority carrier lifetime measurements

“…The excitation wavelength of the TMR system is 1535 nm, and the room-temperature absorption coefficient (α) of GaAsSb is 10484 cm -1 at this wavelength. 7 The photoluminescence (PL) spectra of our GaAsSb p-i-n sample at room temperature is shown in Fig. 2.…”

“…8 Recently, a SACM APD with GaAsSb absorber and AlGaAsSb multiplier on InP has been demonstrated with high gain and low excess noise. 7 However, the device's dark current was high compared to a commercial InGaAs-based APD. 9 Minority carrier lifetime (τMC) can be related to the diffusion component of dark current (Jdiff) through:…”

“…3 GaAs0.5Sb0.5 (GaAsSb) is a candidate for the absorber because its use in a SACM structure using the low-noise 4,5 multiplier AlxGa1-xAsySb1-y eliminates a conduction band offset between the charge and multiplication layer. 6,7 Early studies of GaAsSb-based photodetectors on InP have demonstrated promising D.C. performance for high-speed SWIR applications. 8 Recently, a SACM APD with GaAsSb absorber and AlGaAsSb multiplier on InP has been demonstrated with high gain and low excess noise.…”