Available online at www.sciencedirect.com ScienceDirect Materials Today: Proceedings 5 (2018) 10028–10033 www.materialstoday.com/proceedings 2214-7853© 2017 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Functional Nano-Materials, 2016. IC-FNM 2016 Effect of centrifugation time on the optical properties of colloidal silicon nanoparticle Susmita Biswas a,* , Anupam Nandi a , Arnab Dhara c , Apurba Baral c , Hiranmay Saha a , Nillohit Mukherjee a , Syed Minhaz Hossain b a Center of Excellence for Green Energy and Sensor Systems, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, West Bengal, India 711103 b Department of Physics, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, West Bengal, India 711103 c Dr. M. N. Dastur School of Materials Science and Engineering, Indian Institute of Engineering Science and Technology, Shibpur, Howrah, West Bengal, India 711103 Abstract We report synthesis of colloidal suspension of silicon (Si) nanoparticle (NP) with native silicon dioxide (SiO 2 ) layer by mechanical milling. Different size distribution of Si NPs in the colloid has been obtained by varying the centrifugation time. Width of the particle distribution curve of Si NPs was found to decrease with increasing centrifugation time of the colloidal suspensions, which has been established from the FESEM analysis. The variation of particle size also put its signature in the photoluminescence (PL) properties of the prepared materials. © 2017 Elsevier Ltd. All rights reserved. Selection and/or Peer-review under responsibility of International Conference on Functional Nano-Materials, 2016. Keywords: Silicon nanoparticles; mechanical milling; centrifugation; optical properties; optoelectronic material. 1. Introduction Optoelectronic materials have drawn significant attention in the field of modern science and technology. Efficient room-temperature photo luminescence is one of the quantum confinement induced electronic properties of silicon (Si) nanoparticles (NP) capped by silicon dioxide layer [1]. If we consider the origin of photo luminescence in * * Corresponding author. Tel.: +91 3364551644; fax: +91 3364551644 . E-mail address: sabitasusmita@gmail.com