▁▁ 2 ▁N H 4 + ▁ ▁Cad m ium ▁sul f ide ▁can ▁be ▁produced ▁using ▁metal organ ic ▁v ap our ▁phase ▁ep it axy ▁and ▁MO C VD ▁techniques ▁by ▁the ▁reaction ▁of ▁dim eth yl c ad m ium ▁with ▁di eth yl ▁sul f ide : ▁ ▁C d ( CH 3 ) 2 ▁ ▁+ ▁Et 2 S ▁ ▁→ ▁▁ ▁C d S ▁ ▁+ ▁ ▁CH 3 CH 3 ▁▁ ▁+ ▁ ▁C 4 H 1 0 ▁Other ▁methods ▁to ▁produce ▁films ▁of ▁C d S ▁include ▁Sol ▁gel ▁techniques ▁S put ter ing ▁Elect ro chem ical ▁de position ▁Sp ray ing ▁with ▁prec ursor ▁cad m ium ▁salt , ▁sul fur ▁comp ound ▁and ▁dop ant ▁Screen ▁printing ▁using ▁a ▁sl ur ry ▁containing ▁dispers ed ▁C d S ▁ ▁Re actions ▁Cad m ium ▁sul f ide ▁can ▁be ▁dissol ved ▁in ▁ac ids . ▁C d S ▁ ▁+ ▁▁ 2 ▁H Cl ▁▁ ▁→ ▁▁ ▁C d Cl 2 ▁ ▁+ ▁ ▁H 2 S ▁ ▁When ▁solutions ▁of ▁sul f ide ▁containing ▁dispers ed ▁C d S ▁particles ▁are ▁ir rad i ated ▁with ▁light ▁hydro gen ▁gas ▁is ▁generated : ▁ ▁H 2 S ▁→ ▁H 2 ▁+ ▁S ▁▁▁▁▁▁▁ Δ H f ▁= ▁+ 9 . 4 ▁k cal / m ol ▁The ▁proposed ▁mechanism ▁involves ▁the ▁electron / hole ▁pairs ▁created ▁when ▁incident ▁light ▁is ▁absor bed ▁by ▁the ▁cad m ium ▁sul f ide ▁followed