Photoluminescence mapping of mid-wave infrared InAs/GaSb type II superlattice: Influence of materials and processes on spatial uniformity
Artikel i vetenskaplig tidskrift, 2023

The imaging performance of infrared focal plane array (FPA) is limited by the non-uniformity of the in-plane response of InAs/GaSb type II superlattices (T2SL) consisting of a few hundred or more thin layers. Fundamentally, the non-uniformity results from the materials’ property variation and process fluctuations over an area of a square centimeter. Thus, the influence of materials and processes on the uniformity of internal response is necessary to accurately detect and evaluate to improve the imaging performance of an FPA detector. In this work, spatially resolved photoluminescence (PL) was implemented to detect the microscale mesa pixels, and the effects of materials and processes on spatial uniformity were studied for the first time. Modulated PL-mapping technology based on step-scan Fourier transform infrared spectrometry was used to extract parameters from each test spectrum, such as PL peak energy, linewidth, and integral intensity, which were then analyzed by 2D spatial mapping. Results showed that the variation of T2SL material properties accounted for 29% of the non-uniformity, and the remaining 71% resulted from the process fluctuation. In particular, the etching process had a great influence on the uniformity. The non-uniformity of the integral intensity of the sample after etching increased by 2.44 times compared with that before etching. Thereafter, a layer of SiO2 film was deposited to passivate the surface. The results showed that the non-uniformity returned to the level before etching, which directly proves that the passivation process can improve the response uniformity of the infrared FPA detector.

Midwave infrared

Materials and processes

Photoluminescence mapping

Focal-plane array

InAs/GaSb type-II superlattice

Författare

Zhangyong Shi

Ningbo University

Dingyu Yan

Ningbo University

Yanchao Zhang

Ltd

Fan Zhang

Ltd

Yimin Chen

Ningbo University

Chenjie Gu

Ningbo University

X Chen

Chinese Academy of Sciences

Jun Shao

Chinese Academy of Sciences

Shumin Wang

Chalmers, Mikroteknologi och nanovetenskap, Fotonik

Xiang Shen

Ningbo University

Journal of Alloys and Compounds

0925-8388 (ISSN)

Vol. 947 169410

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Annan materialteknik

DOI

10.1016/j.jallcom.2023.169410

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Senast uppdaterat

2023-03-23