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Single crystal Mo thin films are successfully grown on single‐crystal sapphire {0001} substrates using a newly developed two‐step sputtering method. Cu(In1‐x,Gax)Se2 (CIGS) thin films are then epitaxially grown on the Mo thin films by three‐stage co‐evaporation. Following that, a CdS buffer layer is deposited on the epitaxial (epi)‐CIGS thin films by a chemical bath deposition (CBD) method, leading to the overall epitaxial relations such as CdS{111}//CIGS{112}//MoSe2{0001}//Mo{110}//sapphire {0001}. The Cd‐diffusion into the CIGS occurs to approximately 30 nm from the CIGS/CdS interface boundary together with depleted Cu at the CIGS surface region. This suggests that Cd diffuses through Cu vacancies in the intra‐grain rather than at the grain boundaries. Two distinct solar cells are fabricated using epi‐ and polycrystalline (poly)‐CIGS thin films deposited on sapphire substrates in the same deposition run. The open‐circuit‐voltage (VOC) of epi‐CIGS solar cell is found to be higher than poly‐CIGS solar cell. The net carrier concentration (NCV) derived from the capacitance‐voltage (C‐V) measurements of epi‐CIGS solar cell is 3.5 times higher than poly‐CIGS solar cell, suggesting one of the causes of higher VOC. This large difference in the NCV is discussed based on the results of low‐temperature photoluminescence measurements. [ABSTRACT FROM AUTHOR]

T lymphocytes are the central coordinator and executor of many immune functions. The activation and function of T lymphocytes are mediated through the engagement of cell surface receptors and regulated by a myriad of intracellular signaling network. Bioengineering tools, including imaging modalities and fluorescent probes, have been developed and employed to elucidate the cellular events throughout the functional lifespan of T cells. A better understanding of these events can broaden our knowledge in the immune systems biology, as well as accelerate the development of effective diagnostics and immunotherapies. Here we review the commonly used and recently developed techniques and probes for monitoring T lymphocyte intracellular events, following the order of intracellular events in T cells from activation, signaling, metabolism to apoptosis. The techniques introduced here can be broadly applied to other immune cells and cell systems. This article is categorized under: Immune System Diseases > Molecular and Cellular Physiology Immune System Diseases > Biomedical Engineering Infectious Diseases > Biomedical Engineering., (© 2020 Wiley Periodicals LLC.)