https://scholar.dgist.ac.kr/handle/20.500.11750/243 2026-10-28T21:21:53Z 2026-10-28T21:21:53Z Satale, Vinayak Vitthal Chowdhury, Sagnik Ko, Keum-Jin Karim, Abrar Mohamed, Asmaa Kim, Do-Hyung Lee, Jong-Soo Kang, Jae-Wook https://scholar.dgist.ac.kr/handle/20.500.11750/60954 2026-10-23T05:40:11Z 2026-07-31T15:00:00Z

Title: Micro-molecule modifier enables prolonged shelf-life of perovskite ink for efficient and scalable inkjet-printed solar cells Author(s): Satale, Vinayak Vitthal; Chowdhury, Sagnik; Ko, Keum-Jin; Karim, Abrar; Mohamed, Asmaa; Kim, Do-Hyung; Lee, Jong-Soo; Kang, Jae-Wook Abstract: Stable, eco-friendly perovskite inks are essential for developing scalable, efficient perovskite solar cells (PSCs). Herein, a micro-molecule modification strategy using propylene carbonate (PC), a Lewis base with a strong dipole moment, is employed to enhance the stability and processability of perovskite eco-inks. Incorporating 3 vol% PC significantly prolongs ink shelf-life by more than 15 days, suppresses byproduct formation, and prevents nozzle clogging, while delivering exceptional film-thickness uniformity (similar to 96%) and a smooth surface morphology. Ambient-processed inkjet-printed (IJP) PSCs fabricated with PC-modified inks achieve a powerconversion efficiency (PCE) of 18.59%, surpassing the unmodified control (17.38%), and retain >90% of their initial PCE after nine days (three days for reference) of ink storage under highly humid conditions. This enhancement is attributed to the improved microstructural homogeneity, larger grain formation, and effective grain-boundary passivation induced by the dipolar micro-molecule additive. The micro-molecule modifier controls defect formation in perovskites, as confirmed by a DFT study. The estimated upscaling factor for the micro-molecule-modified device to mini module is 11.9% rel/dec (relative upscaling loss per decade) (similar to 13.5% rel/dec for reference). These findings establish micro-molecular engineering as a sustainable pathway for stable, high-performance, and scalable perovskite photovoltaics, paving the way for industrial IJP applications.

2026-07-31T15:00:00Z Jeong, Seock-Jin Ko, Hyun Woo Jo, Suyeon Selvaraj, Joicy Kim, Jung-Min Lee, Namji Ahn, Jae-Hyeon Lee, Hyeonchae Jeong, Seungmin Kim, Heedae Seo, Paul Hongsuck Shim, Jae Won Kim, Yonghun Ra, Hyun-Soo Park, Min-Chul Lee, Jong-Soo https://scholar.dgist.ac.kr/handle/20.500.11750/60454 2026-07-17T18:01:10Z 2026-03-31T15:00:00Z

Title: High-Gain Ag2Te/MoS2 Hybrid Photodetectors for Short-Wave Infrared Imaging Author(s): Jeong, Seock-Jin; Ko, Hyun Woo; Jo, Suyeon; Selvaraj, Joicy; Kim, Jung-Min; Lee, Namji; Ahn, Jae-Hyeon; Lee, Hyeonchae; Jeong, Seungmin; Kim, Heedae; Seo, Paul Hongsuck; Shim, Jae Won; Kim, Yonghun; Ra, Hyun-Soo; Park, Min-Chul; Lee, Jong-Soo Abstract: Physical artificial intelligence has emerged as a pivotal component in next-generation humanoid technologies, including advanced optical sensors, as it enables autonomous acquisition of sensory information. This study reports a high-performance 0D/2D hybrid photodetector using a high-gain Ag2Te/MoS2 hybrid structure for visible to short-wave infrared (SWIR) photodetection, achieved by the absorption of Ag2Te quantum dots in the infrared region (similar to 1450 nm). The Ag2Te/MoS2 photodetector exhibits a high photoresponsivity of around 7.5 & times; 105 AW-1 and a specific detectivity of over 9.9 & times; 108 Jones at 1 & micro;W/cm2 illumination power with a 0.2 V drain bias voltage. Furthermore, depending on the gain of the photodetector, a fast response speed can also be achieved, with rise and decay times as short as 13 and 23 ms. The 0D/2D hybrid devices were successfully implemented in a 32 & times; 32 array format for infrared imaging, with the results demonstrating spatially resolved pattern reconstruction and real-time photoresponse acquisition. By hybridizing quantum dots and 2D materials, the developed photodetector has broad potential applications, including use in highly integrated SWIR image sensors.

2026-03-31T15:00:00Z Lee, Sang-Hyeon Teku, Justice Agbeshie Jeong, Min-Hye Ahn, Jae-Hyeon Chae, Weon-Sik Kwak, Do-Hyun Lee, Jong-Soo https://scholar.dgist.ac.kr/handle/20.500.11750/60453 2026-07-21T01:40:14Z 2026-05-31T15:00:00Z

Title: Electrically Tunable Tunneling and Spectral Response in WSe2/h-BN/CdSe/Graphene Heterostructure Author(s): Lee, Sang-Hyeon; Teku, Justice Agbeshie; Jeong, Min-Hye; Ahn, Jae-Hyeon; Chae, Weon-Sik; Kwak, Do-Hyun; Lee, Jong-Soo Abstract: Mixed-dimensional heterostructures consisting of zero- and two-dimensional materials offer a promising platform for optoelectronic devices, as the versatility of material combination allows tunable optical properties. Bias-induced approaches provide an additional means to tune the optical properties beyond the intrinsic band alignment of van der Waals junctions. Here, bias-induced tunneling characteristics are achieved in vertically stacked WSe2/h-BN/CdSe quantum dots/graphene heterostructures by employing the top graphene electrode to regulate carrier transport across the h-BN barrier. The electrical analyses based on the Simmons approximation demonstrate tunneling-mediated charge transfer through thin h-BN layers and bias-dependent modulation of the barrier height. Furthermore, tunneling-induced exciton dissociation in WSe2 and CdSe QDs is observed through spectral responsivity and scanning photocurrent measurements. This work establishes a voltage-dependent tunneling platform that enables deterministic control of carrier dynamics in mixed-dimensional optoelectronic devices.

2026-05-31T15:00:00Z Lee, Namji Taylor Derrick Allan Choi, Donghyun Kwak, Do-Hyun Lee, Jong-Soo https://scholar.dgist.ac.kr/handle/20.500.11750/60215 2026-04-15T08:10:45Z 2026-01-31T15:00:00Z

Title: Advances in Photopatterning of Quantum Dots: Mechanisms, Materials, and Device Applications Author(s): Lee, Namji; Taylor Derrick Allan; Choi, Donghyun; Kwak, Do-Hyun; Lee, Jong-Soo Abstract: The precise patterning of quantum dots (QDs) is crucial for integrating advanced optoelectronic devices, including quantum dot light-emitting diodes (QLEDs) and photodetectors. However, conventional patterning techniques often suffer from poor film uniformity and degradation of the optical and electronic properties of QDs. Recently, direct optical lithography has emerged as a powerful alternative, enabling high-resolution patterning while better preserving QD integrity. In this review, we summarize the representative photopatterning mechanisms, including ligand exchange, ligand cross-linking, ligand decomposition, and ligand desorption and discuss the associated material considerations, including QDs, surface ligands, and charge-transport layers. We further highlight recent breakthroughs in applying these strategies to QLEDs and photodetectors. Finally, we outline the remaining challenges - including solubility control, industrial scalability, photodamage mitigation, and the optimization of processing conditions - and propose potential strategies for enhancing patterning quality, device performance, and manufacturability.

2026-01-31T15:00:00Z