We report on the demonstration of Al_0.85Ga_0.15As_0.56Sb_0.44 (hereafter, AlGaAsSb) avalanche photodiodes (APDs) with a 1000 nm-thick multiplication layer. Such a thick AlGaAsSb device was grown by a digital alloy technique to avoid phase separation. The current-voltage measurements under dark and illumination conditions were performed to determine gain for the AlGaAsSb APDs. The highest gain was ∼ 42, and the avalanche initiation occurred at 21.6 V. The breakdown voltage was found to be around −53 V. The measured dark current densities of bulk and surface components were 6.0 μA/cm² and 0.23 μA/cm, respectively. These values are about two orders of magnitude lower than those for previously reported 1550 nm-thick AlAs_0.56Sb_0.44 APDs [Yi et al., Nat. Photonics 13, 683 (2019)]. Excess noise measurements showed that the AlGaAsSb APD has a low k of 0.01 (the ratio of electron and hole impact ionization coefficients) compared to Si APDs. The k of the 1000-nm AlGaAsSb APD is similar to that of the thick AlAsSb APDs (k ∼ 0.005) and 5–8 times lower than that of 170 nm-thick AlGaAsSb APDs (k ∼ 0.5–0.8). Increasing the thickness of the multiplication layer over 1000 nm can also reduce k further since the difference between electron and hole impact ionization coefficients becomes significant in this material system as the thickness of the multiplication layer increases. Therefore, this thick AlGaAsSb-based APD on an InP substrate shows the potential to be a high-performance multiplier that can be used with available short-wavelength infrared (SWIR) absorption layers for a SWIR APD.

中文翻译：

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InP衬底上的低噪声Al0.85Ga0.15As0.56Sb0.44雪崩光电二极管

我们报道了具有0.8纳米厚的倍增层的Al _0.85 Ga _0.15 As _0.56 Sb _0.44（以下称AlGaAsSb）雪崩光电二极管（APD）的演示。通过数字合金技术生长这种厚的AlGaAsSb器件，以避免相分离。进行了在黑暗和光照条件下的电流-电压测量，以确定AlGaAsSb APD的增益。最高增益为〜42和雪崩开始在21.6 V.发生击穿电压被认为是围绕-53 V.测量本体和表面部件的暗电流密度分别为6.0  μ A /厘米²和0.23  μA / cm。这些值比先前报道的1550 nm厚的AlAs _0.56 Sb _0.44 APD的值低两个数量级[Yi等。，纳特。光子学13，683（2019）]。过多的噪声测量表明，与Si APD相比，AlGaAsSb APD的k低（0.01）（电子与空穴碰撞电离系数之比）。所述ķ 1000纳米的AlGaAsSb APD的是类似于厚的AlAsSb的APD（的ķ〜0.005）和5-8倍比170 nm厚的AlGaAsSb的APD（的降低ķ〜0.5-0.8）。将乘法层的厚度增加到1000 nm以上还可以减少k此外，由于在该材料系统中，随着倍增层的厚度增加，电子和空穴碰撞电离系数之间的差异变得显着。因此，InP基板上的这种厚的基于AlGaAsSb的APD表现出了成为高性能倍增器的潜力，可以与SWIR APD的可用短波长红外（SWIR）吸收层一起使用。