Arsenic doped back illuminated blocked impurity band (BIBIB) silicon detectors have advanced near and mid-IR astronomy for over thirty years; they have high quantum efficiency (QE), especially at wavelengths longer than 10 $\mu$m, and a large spectral range. Their radiation hardness is also an asset for space based instruments. Three examples of Si:As BIBIB arrays are used in the Mid-InfraRed Instrument (MIRI) of the James Webb Space Telescope (JWST), observing between 5 and 28 $\mu$m. In this paper, we analyze the parameters leading to high quantum efficiency (up to $\sim$ 60\%) for the MIRI devices between 5 and 10 $\mu$m. We also model the cross-shaped artifact that was first noticed in the 5.7 and 7.8 $\mu$m Spitzer/IRAC images and has since also been imaged at shorter wavelength ($\le 10~\mu$m) laboratory tests of the MIRI detectors. The artifact is a result of internal reflective diffraction off the pixel-defining metallic contacts to the readout detector circuit. The low absorption in the arrays at the shorter wavelengths enables photons diffracted to wide angles to cross the detectors and substrates multiple times. This is related to similar behavior in other back illuminated solid-state detectors with poor absorption, such as conventional CCDs operating near 1 $\mu$m. We investigate the properties of the artifact and its dependence on the detector architecture with a quantum-electrodynamic (QED) model of the probabilities of various photon paths. Knowledge of the artifact properties will be especially important for observations with the MIRI LRS and MRS spectroscopic modes.

中文翻译：

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Si:As IBC 中红外探测器阵列在 5–10 μm 的量子效率和衍射图像伪像：对 JWST/MIRI 探测器的影响

砷掺杂背照式阻挡杂质带 (BIBIB) 硅探测器在近红外和中红外天文学领域取得了超过 30 年的进步。它们具有高量子效率 (QE)，尤其是在波长超过 10 微米的情况下，以及较大的光谱范围。它们的辐射硬度也是天基仪器的资产。詹姆斯韦伯太空望远镜 (JWST) 的中红外仪器 (MIRI) 中使用了 Si:As BIBIB 阵列的三个示例，观察范围在 5 到 28 美元之间。在本文中，我们分析了导致 5 到 10 $\mu$m 之间的 MIRI 设备的高量子效率（高达 $\sim$ 60\%）的参数。我们还对在 5.7 和 7.8 $\mu$m Spitzer/IRAC 图像中首次发现的十字形伪影进行建模，此后也在较短波长 ($\le 10~\mu$m) 实验室测试中成像MIRI 探测器。该伪像是从定义像素的金属触点到读出检测器电路的内部反射衍射的结果。阵列在较短波长处的低吸收使光子衍射到广角，多次穿过探测器和基板。这与其他吸收不良的背照式固态探测器的类似行为有关，例如在 1 $\mu$m 附近运行的传统 CCD。我们使用各种光子路径概率的量子电动力学 (QED) 模型研究了工件的特性及其对探测器架构的依赖性。了解伪像特性对于使用 MIRI LRS 和 MRS 光谱模式进行观测尤为重要。