Pos oleh :

dep_fisika

Publikasi Journal : Wafer-scale transfer route for top–down III-nitride nanowire LED arrays based on the femtosecond laser lift-off technique

Nursidik Yulianto, Andam Deatama Refino, Alina Syring, Nurhalis Majid, Shinta Mariana, Patrick Schnell, Ruri Agung Wahyuono, Kuwat Triyana, Florian Meierhofer, Winfried Daum, Fatwa F. Abdi, Tobias Voss, Hutomo Suryo Wasisto & Andreas Waag
https://doi.org/10.1038/s41378-021-00257-y
Journal : Nature Microsystems & Nanoengineering

Abstract

The integration of gallium nitride (GaN) nanowire light-emitting diodes (nanoLEDs) on flexible substrates offers opportunities for applications beyond rigid solid-state lighting (e.g., for wearable optoelectronics and bendable inorganic displays). Here, we report on a fast physical transfer route based on femtosecond laser lift-off (fs-LLO) to realize wafer-scale top–down GaN nanoLED arrays on unconventional platforms. Combined with photolithography and hybrid etching processes, we successfully transferred GaN blue nanoLEDs from a full two-inch sapphire substrate onto a flexible copper (Cu) foil with a high nanowire density (~107 wires/cm2), transfer yield (~99.5%), and reproducibility. Various nanoanalytical measurements were conducted to evaluate the performance and limitations of the fs-LLO technique as well as to gain insights into physical material properties such as strain relaxation and assess the maturity of the transfer process. This work could enable the easy recycling of native growth substrates and inspire the development of large-scale hybrid GaN nanowire optoelectronic devices by solely employing standard epitaxial LED wafers (i.e., customized LED wafers with additional embedded sacrificial materials and a complicated growth process are not required).

Journal Materials Advances

Publikasi Journal : Room-temperature ppb-level trimethylamine gas sensors functionalized with citric acid-doped polyvinyl acetate nanofibrous mats

Aditya Rianjanu, Rizky Aflaha, Nur Istiqomah Khamidy, Mitra Djamal, Kuwat Triyana and Hutomo Suryo Wasisto
https://doi.org/10.1039/D1MA00152C
Journal : MATERIALS ADVANCES

Abstract

Conventional chemoresistive gas sensors based on inorganic metal oxide semiconductors work typically at an elevated temperature (200 – 500°C) to facilitate the chemical reaction between the target gas molecules and sensing oxide layer. Besides their high operating temperature, these sensors are often found to possess poor selectivity towards a specific analyte. Here, we report on the fabrication and functionalization of electrospun citric acid-doped polyvinyl acetate (PVAc/CA) nanofibers on a quartz crystal microbalance (QCM) chip, which is used as a highly sensitive and selective gravimetric trimethylamine (TMA) gas sensor operating at room temperature. The structural morphology and chemical composition of both undoped and CA-doped PVAc nanofibers were investigated by the scanning electron microscopy (SEM) and the Fourier-transform infrared (FTIR) spectroscopy, respectively. During exposure to TMA vapors, the PVAc/CA nanofiber sensor could obtain a sensing sensitivity of 85.4 Hz/ppm with a limit of detection (LOD) of 19 ppb. Cross-sensitivity tests involving different analytes/gases (i.e., TMA, dimethylamine (DMA), methylamine (MA), ammonia, and water) revealed the high selectivity characteristic of the sensor towards TMA molecules. Besides, decent reversibility and repeatability of the sensor with response and recovery times of 7 and 20 s, respectively, were also demonstrated. Amongst the other recently reported QCM-based TMA gas sensors, the proposed device is superior in terms of sensitivity and LOD. This simple yet low-cost alternative improvement technique based on chemical modification of nanofibers can potentially be employed in food-freshness monitoring system, especially for fishery and seafood products where TMA is employed as their quality indicator (i.e., the primary marker of the fishy odor).

Publikasi Journal : eNose-TB A trial study protocol of electronic nose for tuberculosis screening in Indonesia

Antonia Morita Iswari Saktiawati, Kuwat Triyana, Siska Dian Wahyuningtias, Bintari Dwihardiani, Trisna Julian, Shidiq Nur Hidayat, Riris Andono Ahmad, Ari Probandari, Yodi Mahendradhata
https://doi.org/10.1371/journal.pone.0249689
Journal : PLOS One

Abstract

Even though conceptually, Tuberculosis (TB) is almost always curable, it is currently the world’s leading infectious killer. Patients with pulmonary TB are the source of transmission. Approximately 23% of the world’s population is believed to be latently infected with TB bacteria, and 5–15% of them will progress at any point in time to develop the disease. There was a global diagnostic gap of 2.9 million between notifications of new cases and the estimated number of incident cases, and Indonesia carries the third-highest of this gap. Therefore, screening TB among the community is of great importance to prevent further transmission and infection. The electronic nose for screening TB (eNose-TB) project is initiated in Yogyakarta, Indonesia, to screen TB by breath test with an electronic-nose that is easy-to-use, point-of-care, does not expose patients to radiation, and can be produced at low cost. read more