Vol:.(1234567890) J Mater Sci: Mater Electron (2017) 28:6284–6291 DOI 10.1007/s10854-016-6310-7 1 3 Laser processing of copper sulide thin ilm prepared by spray pyrolysis F. A. Mahmoud 1,2  · W. Magdy 1,2  · A.‑S. Gadallah 3  · Mahmoud Nasr 1,4  · I. M. Azzouz 3   Received: 27 September 2016 / Accepted: 27 December 2016 / Published online: 21 January 2017 © Springer Science+Business Media New York 2017 1 Introduction Copper sulides are considered promising materials of p-type semiconductor. They have variety of scientiic and technological applications for solar energy conversion sys- tems, such as photovoltaic cells [1]. Copper sulides are interesting materials for its good electrical conductivity and ideal characteristics for solar energy absorption [2]. Since 1954, much of interests in copper sulides had been found due to their use in CdS/Cu 2 S hetero-junction solar cells. Cu x S (x = 1.8–2) showed photovoltaic (PV) activity due to the reported energy conversion eiciencies 6–9%, for solar cells with Cu x S (x = 1.8, 2) thin ilm as p-type absorbers [3]. At room temperature, there are at least ive known sta- ble phases of copper sulides of copper-rich stoichiometric composition, such as chalcocite (Cu 2 S), djurleite (Cu 1.95 S), digenite (Cu 1.8 S), anilite (Cu 1.75 S) and covellite (CuS) [4]. All of these phases have p-type semiconductor behavior as result of the copper vacancy defects within the crystal lattice, with band gap energy ranging from 1.2 to 2.74 eV [5–8]. These phases appear in the color range of dark gray to blue-black. The copper-rich phase (Chalcocite, 79.85% Cu) is a blue-black or black crystalline compound [9]. Among these phases, copper sulide (Cu 2 S) (chalcocite) is considered as an ideal absorber and/or p-type semiconduc- tor in photovoltaic conversions. Cu 2 S is one of the prom- ising materials due to good electrical conductivity and its unique characteristics [10, 11]. Diferent techniques were reported to deposit Cu 2 S thin ilms, which can be divided into physical and chemi- cal methods. The most commonly employed processes are vacuum evaporation [12], spray pyrolysis [13–17], chemi- cal bath deposition (CBD) [18, 19], chemical vapor depo- sition [20], successive ionic layer adsorption and reaction Abstract Copper sulide (Cu 2 S) thin ilms were depos- ited by spray pyrolysis technique on glass substrate at 370 °C from aqueous solutions of copper chloride dehy- drate (CuCl 2 .2H 2 O) and thiourea (SC(NH 2 ) 2 ). The sprayed ilm was blackish brown in color, well adhered to the sub- strate, pin-hole free and uniformly distributed. The ilm was treated by a laser beam of 805 nm. The structural, sur- face morphological, optical and electrical properties of the ilms were measured, before and after laser treatment, by means of X-ray difraction, scanning electron microscopy SEM, EDAX, optical transmittance and relectance and two point probe technique. XRD showed close structure of cop- per rich phase (chalcocite, Cu 2 S) for both as-deposited and laser treated ilms. Laser treated ilm showed an increment in the crystallite size, proved by XRD and SEM image. It also showed a red shift in the optical band gap calculations, as well as, a higher electrical conductivity. The electrical conductivity of the sprayed Cu 2 S ilms depends on the stoi- chiometry in the ilms. Both as-deposited and laser treated ilms showed highly absorber coeicient which may have the potential as absorber layer in solid state solar cells. * W. Magdy friend_wafaa@yahoo.com 1 Solid State Physics Department, National Research Center, Dokki, Giza 12311, Egypt 2 Solar Cell Lab, Center of Excellence for Advanced Sciences, National Research Centre, Dokki, Giza, P.O.12311, Egypt 3 Department of Laser Sciences and Interactions, National Institute of Laser Enhanced Sciences, Cairo University, Giza 12613, Egypt 4 Advanced Materials and Nanotechnology, Center of Excellence for Advanced Sciences, National Research Centre, Dokki, Giza, P.O.12311, Egypt