Photovoltaic Metrology Section

Photovoltaic group at CSIR-NPL is the oldest photovoltaic group in the country and has very rich history in silicon based photovoltaics since last four decades, being first to develop silicon solar cells in the country in around mid 70’s. CSIR-NPL is the first laboratory to demonstrate the complete process ‘from metallurgical grade silicon to solar grade polysilicon and fabrication of solar cells.

Current Research Activities:

The photovoltaic metrology group is involved in basic and applied research spanning from wafer based silicon photovoltaic technology, thin film to latest concepts such as organic and perovskites based photovoltaic devices development, testing and measurements. The group is currently engaged in the following R&D activities with an aim to develop efficient and cost effective photovoltaic devices, develop protocols for precise and accurate measurements of PV cells and modules as well as generating skilled manpower for supporting Indian PV sector.

  • Photovoltaic Metrology: Setting national primary standard for solar cell calibration, secondary cell standard and national centre for photovoltaic module testing
  • Validation of solar cell efficiency
  • Silicon-based Photovoltaics: Unit process development for addressing optical, electronic and electrical losses
  • Thin Film Photovoltaics: Amorphous/microcrystalline silicon & HIT solar cells
  • Organic and Perovskites photovoltaic devices
  • PV Modules: Performance analysis, energy yield and degradation related investigations specific to Indian climatic conditions
  • Training Programmes: Solar photovoltaic systems, fundamentals, design and metrology


Ongoing Projects:

  1. National primary standard facility for solar cell calibration; (Project cost: 1788.5 Lakhs; July 2017-2020); Sponsored by Ministry of New and Renewable Energy (MNRE), Govt. of India.
  2. Development of low cost approaches towards high efficiency silicon photovoltaics (In-house Project)
  3. Development of silicon nanowire arrays for effective light harvesting and efficient solar cells; (Project Cost; 25 Lakhs; 2014-2019) under CSIR under Young Scientist awardee research grant.
  4. Development of New Interfacial Layers for Efficient and Stable Excitonic Solar Cells sponsored by SERI, DST, New Delhi from 06/07/2017 to 05/07/2020 (98.2 lakhs).
  5. Semiconducting Thiophene Based Electronic Materials for Organic Solar Cells sponsored by SERB, DST, New Delhi 07/10/2015 to 06/10/2018(32.76 lakhs).
  6. Development of Flexible Perovskite Solar Cells sponsored by CSIR through a CSIR-YSA research grant (2016-2021).
  7. Project on training: Workshop and Training on PV materials, devices and systems sponsored by MNRE.


  • Thermoelectric water-harvesting unit for potable water (FTT)
  • Solar cell validation system (FTT)
  • Development of Infrared (IR) Indian Certified Reference Standard (FTC)

Upcoming project:

Development of interface layer of perovskite solar cells in view of silicon-perovskite tandem solar cell fabrication- DST

Projects executed/accomplished:

  1. Development of Efficient Silicon Photovoltaic Solar Cell (CSIR Network Project under TAPSUN programme) (2012-2017)
  2. R&D on Photovoltaic & Related Energy Applications (CSIR-supra institutional project; 2007- 2012)


The group is well equipped with several state of the art facilities for crystalline silicon solar cell fabrication and PV materials and device characterization.

A. Silicon solar cells processing:

  • 3 sets of diffusion/oxidation furnaces (up to 4 inch wafers processing)
  • ALD (Thermal and plasma assisted, PICOSUN)
  • RTP (AnnealSys, AS-One 150, France)
  • Laser Scriber (Yuhan Sonic, China)

B. Test & Measurement of PV devices:

  • I-V measurement system with Class AAA Sun Simulator (21x21 cm2, AM1 & AM1.5 solar spectrum) (Newport/Oriel)
  • SR and I-V tester (CEP-25HS-50SR Japan) (5x5 cm2)
  • Non-contact measurements (m-PCD, SPV, LBIC) (Semilab, WT 2000 P) ,
  • Sinton’s Lifetime tester and Sun Voc measurement set up
  • Four Point Probe (Quad Pro, Lucas USA)




Dr. Sushil Kumar, Senior Principal Scientist


Dr. Jeyakumar Ramanujam, Principal Scientist
Dr. Asit Patra, Principal Scientist
Dr. Sanjay Kumar Srivastava, Principal Scientist
Dr. (Ms.) Vandana, Principal Scientist
Dr. Pankaj Kumar, Principal Scientist
Dr. Jai Prakash Tiwari, Principal Scientist
Dr. Rajiv Kumar Singh, Principal Scientist
Dr. P. Prathap, Senior Scientist
Dr. (Ms.) Rachna Kumar, Senior Scientist

Technical Support:

Mr. Chandra Kant, Principal Technical Officer
Ms. Subha Laxmi, Technical Officer
Dr. Neeraj Chaudhary, Technical Officer
Ms. Kalpana Lodhi, Technical Assistant
Mr. Brijesh Kuamar Sharma, Sr. technician (2)
Mr. Ram Rajjan, Lab Assistant


Silicon Thin Film Photovoltaic

Research: Summary of the research activity, key topics 


The group has several deposition systems and in-house characterization facilities. We have two plasma enhanced chemical vapour deposition (PECVD) systems for deposition of amorphous & micro/nano-crystalline silicon films: (a) Single Chamber & (b) Multi-chamber PECVD systems and also sputtering & thermal evaporation systems for deposition of metallic & other layers for solar cells. The group has various characterization facilities such as IV-CV, temperature dependent dark & photo conductivities, solar simulator, stylus based thickness profilometer, stress measurement setup, laser Raman, photothermal deflection spectroscopy (PDS) & constant photocurrent method (CPM) etc.

Deposition system:

Multi-chamber PECVD system

Characterization facilities:

Amorphous & Microcrystalline silicon thin film deposition and solar cell fabrication

Simulation work for efficient solar cells

Diamond like carbon (DLC) thin films for solar cells application:

Some recent patents & publications

Organic Photovoltaic Activities

Organic photovoltaics (OPV) is fast emerging potential renewable, lightweight, large area and low-cost solar cell technology. Recently, the power-conversion efficiency of state-of-the-art in polymer solar cells (PSCs) has exceeded 9% and further enhancements in the efficiency towards 10% (the threshold for commercial applications) are required. Current international R&D efforts in OPV are focussed towards developing high efficiency and stable devices with both conventional and inverted solar cell configurations based on donor :acceptor bulk heterojunction concept using the soluble polymers/small molecules (electron donors) and modified fullerenes (electron acceptor) in combination with suitable interface layers. OPV group at CSIR-NPL is a very active, vibrant and internationally known centre and is carrying out R&D work on above two approaches by way of addressing the fundamental and applied facets of organic materials and devices and have already achieved efficiency in excess of 6% under CSIR TAPSUN solar energy initiative.

R&D activities

The R&D activities in our group is concentrate on device fabrication for solar cell based on polymers, hybrid polymer inorganic nano-structure, quantum dots and small molecule semiconductors: studies of hole transport layer (HTL), electron transport layer (ETL), photovoltaics, nanoscale characterization, Impedance spectroscopy and optimization of buffer layer etc. for the development of efficient stable solar cell. Other R&D activities are solution route for synthesis of various metal oxide as buffer layers, in situ synthesis of semiconductor nanoparticles in polymer matrix to modify the active layer for solar cells and nanocrystalline semiconductors by colloidal route

Recently, our group has started R&D work on design and synthesis of donor and acceptor materials for organic solar cell to improve the PCE and lifetime of the devices. Major activities in this are : a) Synthesis and characterizations of donor-acceptor polymers and small molecules; b) Synthesis of fullerene based new acceptor molecules; c) electrochemistry.

In essence the activities of OHSC group are classified in two categories as mentioned below.

1. OPV Material development

2. OPV Device Development